GENERAL PROBLEMS OF NEMATOLOGY

O.N. PUGACHEV, S.J. TSALOLIKHIN & A. RYSS
Zoological Institute, Russian Academy of Sciences
Universitetskaya naberezhnaya, 1, St. Petersburg, 199034, Russia

ZOOLOGICAL INSTITUTE, RUSSIAN ACADEMY OF SCIENCES AND NEMATOLOGY RESEARCH IN RUSSIA

In 1999 Russian Academy of Sciences celebrates its 275^th anniversary. Academy was founded in St. Petersburg and Zoological Institute (Museum) was one of its first centers. At present the Zoological Institute and Botanical Institute RAS are the largest centers of the biological collections in Russia, newly independent countries of the former Soviet Union, East and Central Europe. Basic goal of scientific research being conducted by the Zoological Institute during the three centuries, is the study and conservation of biodiversity on the giant territories of Russia. Fundamental research includes systematics, faunal studies, zoogeography and evolution of animals of Russia and neighbouring countries, Professor Ivan Filipjev, founder of the Russian Nematology, was scientific worker of our institute. His type materials are deposited in the Collection of the Zoological Institute, as the separate unit. This year is the year of 110^th anniversary of this world-known scientist. 1999 is the year of 100^th anniversary of Dr. Ekaterina Kirjanova, the most recognized Russian taxonomist who worked on plant parasitic, soil, entomopathogenic nematodes and nematomorphas. She worked all her life in Zoological Institute and created the large collections of the above mentioned taxa. At present Dr. S. Tsalolikhin & Dr. A.Ryss continue the research on nematode taxonomy and evolution, and Dr. V. Galtsova and E. Kulangieva – on ecology of nematodes. Russian nematologists use the Nematode Collection of the Zoological Institute, make contributions to the collection and curry out the collaborative research with Zoological Institute. Among other nematology centres in Russia the following ones have to be mentioned: Academy of Science: Institute of Parasitology, Institute of the Inner Water Bodies, Institute of Biology (Karelian Branch RAS), Biology & Soil institute, Marine Biology Institute; St. Petersburg, Moscow and Vladivostok State Universities and many other institutions. The Third International Nematology Symposium is devoted to the wide spectrum of problems of fundamental and applied nematology, from molecular evolution till the nematode management and control. Presentations and discussions of the Symposium will favor the further progress of the fundamental and applied nematology research in Russia, and, possibly, in the world. We gratefully acknowledge the support of the Russian Foundation for Basic Research, assistance of the General Biology Branch RAS, State Quarantine Service of the Russian Federation, Society of Nematologists, Russian Parasitological Society, Department for Environmental Protection - Committee for Municipal Management of St. Petersburg & the computer firm Svega Pro.

GENERAL PROBLEMS OF NEMATOLOGY

Molecular Evolution

N.B. PETROV¹, O.G. MANYLOV², V.V. ALESHIN¹, N.S. VLADYCHENSKAYA¹, O.S. KEDROVA¹, & I.A. MILYUTINA¹.
Are there molecular evidences for the closest relationship of the Nematoda with Gastrotricha?
Cladistic analyses of morphological characters suggest the Nematoda to be a sister group of the Gastrotricha. On the contrary, recent analyses of the 18S rRNA gene sequences place the Nematoda in a hypothetical clade of molting animals "Ecdysozoa", or cluster them with Chaetognatha, while the Gastrotricha, represented by the specialized order Chaetonotida, are placed outside these groups. In order to resolve this controversy, we re-examined the relationships of the Nematoda, using additionally the 18S rRNA sequence of Turbanella comuta, a species from the gastrotrich order Macrodasyida. Depending on taxon sampling, the Nematoda and Gastrotricha moved from basal to apical position in the 18S rRNA trees, but only occasionally appeared as sister groups. The greatest number of apomorphies in 18S rRNA sequences, shared with Nematoda, was observed in Gnathostomulida, Chaetognatha, and "Ecdysozoa". However, these characters do not form a clearly distinguishable common synapomorphic complex, being randomly distributed among all these taxa. Thus, the 18S rRNA data do not support the closest relationship of the Nematoda with Gastrotricha.
¹Section of Evolutionary Biochemistry. A.N. Belozersky Institute of Physicochemical Biology. Moscow State University. Moscow. 119899. Russia: Tel. 095 939 14 40. fax 7 095 939 31 81. email petr@bioevol.genebee.msu.su;²Department of Invertebrate Zoology. St. Petersburg State University, St.Petersburg, 199034, Russia, tel.: 7 812 328 9688. E-mail: oleg@ogm.usr.pu.ru

L . Yu. RUSIN, V.V. ALESHIN, O.S. KEDROVA, I.A. MILYUTINA, N.S. VLADYCHENSKAYA & N.B. PETROV.
Molecular evidence for phylogenetic reliability of Araeolaimida sensu stricto.
The order Araeolaimida is assumed to be an artificial group including some forms which appear as transition to other orders and subclasses that led to its abandonment within some classifications. A phylogenetic analysis of the 18S nematodes rRNA sequences within the complex of Monhysterida-Secernentea including species Axonolaimus spinosus revealed that Araeolaimida branches off independently from the general nematode stem. A true filiation in this part of the nematode phylogenetic tree is as follows: (Monhysterida (Araeolaimida (Plectida (Teratocephalida, Secernentea)))). Analysis of apomorphic characters specific to the nodes of this filiation suggests that Axonolaimus spinosus has already acquired all the synapomorphic characters of "secementean stem" region of hairpin 49 of the 18S rRNA secondary structure attributable to Monhysterida-Secernentea complex. Thus, data obtained underlay the necessity to revive the order Araeolaimida s. str. while groups Araeolaimida s. str. + Plectida + Teratocephalida + Secernentea as well as Araeolaimida s. str. + Monhysterida appear to be paraphyletic.
Section of Evolutionary Biochemistry, A.N. Belozersky Institute of Physicochemical Biology. Moscow State University, Moscow, 119899, Russia, tel.: 095 939 14 40, fax: 7 095 939 3181, E-mail: petr@bioevol.genebee.msu.su

Morphological Taxonomy and Evolution

A. CUNHA¹, R.B.R. AZEVEDO¹, S.W. EMMONS² & A.M. LEROI^1,2.
Not all nematodes have constant cell numbers.
Nematodes are generally considered to have an adult cell number that does not vary among wildtype individuals as a consequence of invariant cell lineages. In a comparative study of 13 free-living nematode species, we show that the adult epidermis of most species contains variable numbers of nuclei. This variance is positively correlated with mean epidermal nuclear number. Simulations of the lateral seam cell lineages of four species show that variance in cell number is influenced by lineage topology, as well as by the frequency of lineage variants. We show that the epidermal variability of Panagrellus redivivus cannot be accounted for by the complexity of its lineage, but requires higher levels of lineage variability, than are found in Caenorhabditis elegans, Oscheius myriophila and Rhabditella octopleura. Our findings suggest that many nematodes may have tissues composed of indeterminate numbers of cells formed from variable lineages and, as such, resemble other metazoans.¹Department of Biology, Imperial College, Silwood Park, Ascot, Berkshire SL5 7PY, UK. tel.: +44 1344 294335, fax: +44 1344 294339, E-mail: a.leroi@ic.ac.uk;²Department of Molecular Genetics, Albert Einstein College of Medicine, Bronx, New York 10461, USA

V.V. GALTSOVA¹, L.V. KULANGIEVA¹, Ya.I. STAROBOGATOV¹, V.F. LEVCHENKO² & A.V. SPIROV².
Digital image analysis techniques in taxonomy of nematodes and other invertebrates.
Digital image analysis techniques offer alternative ways to differentiate morphological features in microscopic images of nematodes, allowing an automated approach to their identification and classification. There are three main directions in this process. The first is concerned with the algorithms of processing images. Since 1992 we began to work in this direction. We developed the software SABATIERIA (Galtsova, Kulangieva, 1994) and image analyzing system NEMATOLOGIST which are intended for the work with computer images of nematodes (Galtsova, Kulangieva, 1999). The second position is connected with the working out of recognition techniques to define the different shapes and structures in images under study. We offered and developed Mobile Genetic Elements technique on the basis of connected approach – combination of Neural Networks with Genetic Algorithms (Spirov, 1996). We are going to apply software packages for the recognition and classification of images. This work will be done on databases of freeliving marine nematodes and mollusks. The last direction is the use artificial intelligence techniques for identifying, classifying, or making decisions by combining the information supplied from two previous directions. We proposed the conceptual scheme of the expert system ZOOARM for the identification of invertebrate animals (Galtsova et al, 1995). It includes database of object, database of knowledge, keys for identification, classificator of taxa and classificator of features. We began to realize this project for nematodes and shells. Support: INTAS (grant 97-30950.¹Zoological Institute RAS, St.Petersburg 199034, Russia, tel.: 7 812 3281212, fax: 7 812 3282941, E-mail: gvv@eti.mail.iephb.nw.ru;²Institute of evolutionary physiology and biochemistry RAS, St.Petersburg 194223, Russia, tel./fax: 7 812 5523219, E-mail: lew@ief.spb.su

D.M. MILJUTIN & A.V. TCHESUNOV.
On anatomy of adult female of Benthimermis megala (Nematoda, Benthimermithidae), a deep-sea parasite.
The nematodes of family Benthimermithidae are rare and poorly studied parasites of various deep-sea benthic invertebrates. The larvae parasitize in hosts’ body cavities and internal organs, but adult worms go out to environment where they do not feed but reproduce. The construction of benthimermithids has features of marine free-living nematodes (head and body setae, amphids situated far from the cephalic apex), which combine with the strongly modified alimentary tract. However internal structures of benthimermithids are studied poorly. We examined the anatomy of Benthimermis megala Petter 1987, the biggest species of benthimermithids. The adult free-living females were collected in the Norwegian Sea at the depth 1478-1780 meters. Neither larvae and males of this species nor hosts of larvae are known. Body length 78,5-148 mm. Hypodermis with eight chords. Musculature coelomyaric, up to 1600 cells on the cross-section. Nerve ring immersed inside the anterior trophosome. The mouth absent. Pharynx thin, none muscular, without internal lumen. Midgut modified to trophosome, which has a cellular construction and thin internal lumen, i. e. keeps the architectonics of the real midgut. Rectum vestigial or absent. Female genital system amphidelphic. Germinal zone of ovaries allocated along entire ovary (hologonic ovary) then the germinal zone of the rest, smaller species of Benthimermis is terminal (telogonic ovary) (Petter, 1980, 1981, 1983, 1987; Chesunov, 1988). Spermatheca is not found. The project is supported by the foundation “Russian Universities - Fundamental Studies”.
Department of Invertebrate Zoology, Faculty of Biology, Moscow State University, Moscow, 119899, Russia, tel.: (095)939-36-56, E-mail: hemulek@mail.ru; avt@atchesunov.home.bio.msu.ru

B.V. ROMASHOV¹ & J.V. NECRASOV².
The morphological and morphometrical characters in the taxonomy of nematodes-capillariides (Nematoda, Capillariidae).
There are considerable materials in the morphology and taxonomy of Capillariidae. The wide spectrum of morphological and morphometrical characters are used in the taxonomy to differentiate these nematodes. The important problem is the systematization of morphological characters and the interpretation their taxonomic values. We propose a system of morphological-taxonomic characters, which can be used in the morphological research of the capillariides. Characters are subdivided into metrical and non-metrical (meristic and qualitative) ones, they are systematized into four groups. The first group (metrical) defines the body size and the sizes of the body parts. The second (metrical) group defines the sizes of organs and their fragments. The third (meristic) group describes the numbers of different morphs and the fourth group (qualitative) describes the form and the design of different morphs. 40 metrical and 20 meristic and qualitative characters are selected. The metrical characters can be estimated using comparative indicies. The position of spicule in relation to pseudocloacal canal is the major sinapomorphy which divides the family Capillariidae into two groups. The groups are nearly equal and correspond to two genera: Capillaria Zeder, 1800 and Eucoleus Dujardin, 1845.¹Voronezh Biosphere Reserve, Voronezh, 394080;²Voronezh State Agrarian University, Voronezh, 394001, E-mail: Voronezh.reserve@p70.fl6.n5025.z2.fidonet.org

A. RYSS & A. LOBANOV.
Principles of taxonomic identification illustrated on nematode computer keys.
Main peculiarities of the computerized key can be divided in 2 groups - the structural (peculiarities of the key database), and the dynamic ones (specific features of the identification step). Among structural features the following ones the most important: 1) number of entries to start the new diagnosis. There are monoentry keys and polyentry ones.2) the number of states of character. There are dichotomous keys and polychotomous ones. 3) Possibility to use the images of characters and character states to operate the identification. There are image-operating keys and wording-operating ones. 4) capability to operate quantitative characters and statistics. Most important dynamic features of the key are the following: 1) interactivity, i.e. capability to dialogue with the user; 2) number of characters used at each identification step, consequently, there are mono-character step keys and multi-character step keys. The latter type allows sometimes to reach identification in one step, it has preferences in diagnosis of taxa with numerous quantitative characters, e. g. nematodes (see Ryss, 1997a, 1997b). 3) use of special built-in algorithms to calculate the diagnostic value of characters at each step of identification. The sense of algorithm is to split the current set of taxa to minimum subsets and thus to make shorter the average path of identification. At each step the program proposes the character in the order depending on their diagnostic values. User can use any character that seems more convenient to him, but in the last case the path will be longer. Above-mentioned principles are illustrated on the author computer keys of the different nematode taxa.
Zoological Institute RAS, Universitetskaya nab., 1, 199034, St. Petersburg, tel.: +7 812 3280611, fax: +7812 5526435, E-mail: alexryss@AR4280.spb.edu

M.A. SHATALOVA & A.V. TCHESUNOV.
The family Ceramonematidae (Leptolaimina): evolutionary trends and generic classification.
The plesiomorph condition of the cuticle in Ceramonematidae is a great and uncertain number of cuticular equally narrow rings devoid of zygapophyses (Dasynemella, Metadasynemella, Metadasynemoides, Pterygonema). The apomorph condition is characterised with reduced (up to near 100) and stabilised ring number; the rings are complicated with additional structures, zygapophyses; ring width varies regularly along the body. The genera Ceramonema and Pselionema possess the most apomorph conditions (i. e. cuticular rings, cephalic sensilla pattern, derived pharynx consisting of muscular procorpus, narrow isthmus and glandular bulb). The primitive genera contain few species and are confined with coarse sands of shallow waters. On the contrary the derived genera Ceramonema and Pselionema contain each a large number of species dwelling in a broad range of sediments from sands to silts and depths from tidal zone to abyssal. The generic composition of the family is revised.
Department of Invertebrate Zoology, Faculty of Biology, Moscow State University, Moscow, 119899, Russia, tel.: 095 939 36 56, E-mail: tches@1.inv.bio.msu.ru; avt@ATchesunov.home.bio.msu.ru

A.V. SHOSHIN¹& A.A. SHOSHINA².
The structure of the stoma tobrilids.
The detection of a number unusual tobrilids in fauna of Baikal Lake has forced the authors to develop an original terminology of the description of the head and stoma tobrilids. The following cross structures considered to be convenient differentiation units of stoma: sutura stomalis (stomatoidal ring), linea margines oesophagus (oesophageal ring), forward and back borders of stoma pockets. 4 stoma regions are allocated: cheilo-, pro-, deutero-, and tritostom (or stoma pockets). The unknown third dorsal reduced stoma pocket is described. The proposed terminology serves for the description of numerous evolutionary transformations of stoma in the new species baikalian tobrilids.¹Institute of Ecology of the Volga River Basin, ul. Komzina 10, Togliatti, 445 003, tel.: (8469) 48 94 97, E-mail: star@infopac.ru;²Samara State Pedagogical University, Valeological Department, ul. A.Ovseenko 26, Samara, 446 090.

A.V. SHOSHIN¹& A.A. SHOSHINA²Origin and evolution of the supplementary apparatus of the tobrilids.
Supplemental organs of the tobrilids have been originated from the unspecialized somatic setae. It is illustrated on an example of the genus Asperotobrilus Shoshin, 1991, where except the hypertrophical somatic setae the special short setae present in the precloacal region. Four stages of evolution of the contemporary tobriloids are allocated which correspond to the following 4 types of their supplemental organs: I - supplementum simplex submersum, II - supplementum simplex convexum, III - supplementum compositum infrabulbularis and IV - supplementum compositum suprabulbularis. 9 types of the supplementary apparatus are allocated. Evolution of the supplementary apparatus of the tobrilids went on a way of amplification of the secretory function of supplements, that led to increase of their sizes, complication of structure and reduction in the number of supplements.¹Institute of Ecology of the Volga River Basin, ul. Komzina 10,Togliatti, 445 003, Russia, tel. (8469) 48 94 97, email star@infopac.ru;²Samara State Pedagogical University, Valeological Department, ul. A.Ovseenko 26, Samara, 446 090, Russia.

Biochemistry and Physiology

A.I. GRUZDEV, L.I. GRUZDEVA & T.E. KOVALENKO.
Effect of heavy metals on some energy-metabolism enzymes of nematodes.
Variations in the activity of energy-metabolism enzymes, such as cytochrome c oxidase (CO), aldolase and malate dehydrogenase (MDH) isoenzymes were analysed in the Cephalobus nematodes influenced by different concentrations of lead acetate in long- and short-term experiments. The stress-reaction of CO was revealed. The enzyme activity rose and fell at different toxicant concentrations (from 0,03 to 25 mg/l). Thus, CO activity was the highest at the maximum lead concentration in the short-term experiment (3 days). The level of CO activity was apparently the factor determining the oxidative metabolism. This assumption was confirmed by changes in the contents of reduced protector reagents (ascorbic acid, dithiotreitol) in enzyme samples as compared with CO activity. Activities of the two main MDH isoenzymes MDH100 and MDH98 correlated positively with CO activity at most lead acetate concentrations. MDH45 isoenzyme activity was reciprocal to the other MDH isoenzymes at some toxicant concentrations (in particular for 1.5 and 3.1 mg/l). These data evidenced the different functional roles of the MDH isoenzymes. Aldolase activity varied in the wave-like manner with increasing lead concentrations gradually approaching to the control level. The stress-reaction of the studied energy-metabolism (iso)enzymes indicated the nonspecific cellular adaptation syndrome in nematode adaptations to heavy metal salts. The indulating variations in the activity of the (iso)enzymes evidenced that detoxication processes were bound to various metabolic pathways and energy sources. The results showed that nematodes of the genus Cephalobus are biochemically adaptable. Support: RFBR, grant 98-04-48487.
Institute of Biology, Karelian Research Centre, Russian Academy of Sciences, Pushkinskaya str. 11, Petrozavodsk, 185610, Karelia, tel.: (8142)77 36 22, fax: (8142) 77 98 10. E-mail: gruzdeva@post.krc.karelia.ru

S.N. THOMPSON¹ & E.G. PLATZER².
Occurrence of arginine kinase, an enzyme catalyzing the synthesis of ATP from phosphoarginine, in trichostrongyloids.
Early biochemical efforts to identify functional phosphagens in nematodes were unsuccessful. Subsequent to our identification of phosphoarginine in the rhabditid nematode Steinernema carpocapsae, we examined phosphorus metabolism in the infective larvae of Haemonchus contortus employing in vivo flow nuclear magnetic resonance spectroscopy, a unique NMR application. Signals for ATP and phosphoarginine were clearly evident, and saturation transfer demonstrated the direct transfer of phosphorus between the two high energy metabolites. Arginine kinase was assayed and was moderately active in H. contortus. The Km values for ATP and arginine were 2.34 and 0.54 respectively. In the infectious stage of Nippostrongylus brasiliensis the arginine kinase activity was much greater. Arginine kinase activity was also demonstrated in the adult stage of N. brasiliensis. These data provide evidence for a functional phosphagen in two trichostrongyloid nematodes.¹Department of Entomology, University of California, Riverside, California, USA, tel.: (909)787-4661, fax: (909)787-3086, E-mail: nelsont@mail.ucr.edu;
²Department of Nematology, University of California, Riverside, California, USA, tel.: (909)787-4352, fax: (909)787-3719, E-mail: edward.platzer@ucr.edu

Development: Individual and Population Levels

N.P. FADEEVA & T.G. SOBOLEVSKAJA.
Population dynamics of Oncholaimium ramosum (Nematoda, Oncholaimidae) in chronic polluted cove.
Benthic communities in the most polluted areas of Golden Horn Bay (the Sea of Japan) are not diverse. Only a few species of small polychaetes and large nematodes dominate. In particular, Oncholaimium ramosum occurs at high densities only in heavily polluted areas around the Russian Sea ports (Vladivostok, Nakhodka) almost the whole year. The highest density of O. ramosum was recorded in May. Juveniles dominated in the population. The highest proportion of juveniles has been revealed in October. From April until July females were represented about 20% of the population, the males and females gradually increased to October. The reproductive period started in February-March. The first juveniles resulting from reproduction appeared in March. The overwintered population consisted mainly of small juveniles belonging to the generation of the current year and large fourth-stage the juveniles of the previous year. The large fourth-stage juveniles becoming adult males and females in spring are able to reproduction and produce offsprings and die to autumn. The small juveniles grow in summer and spend the winter in the form of the fourth-stage juveniles. In a polluted cove during a colonization of azoic areas the population dynamics of the dominant euryphagous nematode Oncholaimium ramosum was characterized by very rapid population growth and continuous reproduction.
Far East State University, 8 Sukhanova St., 690000 Vladivostok, Russia. Tel. (4232) 257779, Fax.: (4132) 257200, E-mail: eco@pin.dvgu. ru

M.N. PATEL, R.B.R. AZEVEDO & A.M. LEROI.
If you want to grow faster – moult!
Why do nematodes moult? The answer to this question has been until now not very convincing. Most nematology texts have avoided giving an explanation while a few have merely hinted at a possible environmental adaptation. Surprisingly, no-one had ever measured the growth of a nematode in any great detail. We measured the growth of individual worms of Caenorhabditis elegans from egg hatch to adulthood at 20 ^oC. Growth measurements were made at about 30 minute intervals during each of the four larval stages. We found that during each larval stage, the worms increased in volume in a strictly linear fashion and the rate of growth only changed after each moult. If C. elegans were to grow to adulthood at the rate set by the first larval stage then it would take 173 hours against 43 hours that it actually takes. Our finding may provide an explanation for the existence of moulting in nematodes.
Department of Biology, Imperial College of Science, Technology and Medicine. Silwood Park, Ascot, Berkshire SL5 7PY, UK. tel.: +44 1344 294335, fax: +44 1344 294339, E-mail: m.n.patel@ic.ac.uk

M.N. PATEL & A.M. LEROI.
Caenorhabditis elegans, large and small.
Caenorhabditis elegans lends itself extremely well to the study of body-size determination. Our work has focused on characterising the growth dynamics of some well-known body-size mutants of C. elegans (including sma, lon and dpy). We have also examined a group of egg laying mutants (egl). Adults of egl-4, egl-19 and egl-25 have already been noted as being larger than the wildtype Bristol N2. However, one characteristic phenotype of egls is the bloating effect of egg retention. The larger size of egl-4 was the result of bloating but this was not the case in egl-19 and egl-25, which were ca. 50% longer and ca. 70% larger by volume. In addition, egl-19 had a faster growth rate from the onset of hatching. We looked at a further 44 known egl loci and measured their body-size at 48 hours after hatching (at 20 ^oC). At 48 hours, before they bloat, 9/44 of the surveyed alleles were longer (ca. +10%) and larger by volume (ca. +33%) compared to N2. Why? There are, roughly, two kinds of egls: those that affect hermaphrodite specific neuron (HSN) migration and fate, and those that affect muscle form or function. We knew that egls of the latter kind were sometimes larger; for example egl-19 encodes an ion channel subunit. However, of the 9 giants identified in our survey, 6 loci were HSN defective and 2 loci were components of a fibroblast growth factor pathway. Could these loci be involved in a new growth control pathway independent of the well-known TGF-b pathway?
Department of Biology, Imperial College of Science, Technology and Medicine. Silwood Park, Ascot, Berkshire SL5 7PY, UK. tel.: +44 1344 294335, fax: +44 1344 294339, E-mail: m.n.patel@ic.ac.uk

A.S. SUSULOVSKY.
Morphology and postembryonal development of species from the genus Comiconchus Jairajpuri et Khan, 1982 (Mononchida).
The detailed morphological study of two species from the rare genus Comiconchus found in Ukraine is carried out. The availability of the ventral longitudional ridge in buccal cavity, the peculiarities of oesophagus base and reproductive system structures in females and males in all probability testify to their propinquity to the specific group zschokkei from the genus Coomansus Jairajpuri et Khan, 1977. The male and complete cycle of postembryonal development of C. trionchus (Thorne, 1924) collected in the Carpathians are described for the first time. It was found, that in contrast to forms with three teeth from the genus Miconchus, three functional and three replacement teeth in comiconchuses are available in buccal cavity already on the first juvenile stage. They are arranged at the bases of corresponding metarhabdions and during the development from stage to stage migrate towards the middle of the buccal cavity. The second species collected in Polissia is new to science.
State Museum of Natural history of NAS of Ukraine, Teatral’na str., 18, L’viv, 290008, Ukraine, tel.: (0322)728917, E-mail: museum@ipm.lviv.ua

Influence of the Ecological Factors on Nematodes

M. AILION¹ & J.H. THOMAS².
Growth of Caenorhabditis species at extreme temperatures.
C. elegans is grown in the lab typically in the 15 to 25° temperature range. While studying dauer formation we discovered that the N2 wild-type strain can grow at a temperature of 27°. At 28° N2 begins to exhibit larval arrest and animals that do grow to the adult stage are sterile. At 29°, N2 arrests at the L1 stage. To see if this temperature response is specific to the N2 strain we looked at the high temperature growth phenotypes of twenty-one naturally isolated strains of C. elegans. Amazingly, all the C. elegans strains showed virtually the same temperature limit for growth (within ~0.5°) as N2 even though they have been isolated from all around the world, covering a wide climatic range. Since C. elegans strains isolated from various places have the same temperature threshold for viability, we reasoned that temperature may be a key parameter in defining the ecological niche of the species. To address this question further, we looked at the temperature thresholds for growth in seven naturally isolated strains of C. briggsae. All seven C. briggsae strains could grow at 30°. We have also examined growth at temperatures below 15°. All twenty-one C. elegans strains could grow at 12.5° with a generation time of about one week. All seven C. briggsae strains grew very poorly at 12.5° with generation times of over two weeks. Thus, temperature may be a key environmental parameter distinguishing these two species, with C. briggsae having a slightly higher optimal temperature.¹Program in Molecular and Cellular Biology;²Department of Genetics, University of Washington, Seattle, WA 98195 USA, tel: (206) 543-3117, E-mail: mailion@u.washington.edu

L.Ja. ASCHEPKOVA & N.P. FADEEVA.
Usage of tolerance functions for a estimate of the realized ecological niches of free-living marine nematodes.
The concept of an ecological niche is closely connected to the concept of the tolerance function. The tolerance to operation of environmental factors was estimated on actually observable numbers of nematodes achieved at various combinations of values of the factors. The material for learning was assembled from 65 samples from a small areas of a part of Amursky Bay, where Razdolnoja river flows into. The tolerance functions were determined for 23 species of free- living nematodes. For these species the tolerance functions were constructed to the following elementary ecological factors: salinity, type of a sediment, contents of organic matter in a sediment and the complex ecological factor – the depth. The approximated tolerance functions were used to estimate of the realized ecological niches of nematodes of Amursky Bay. It is shown, that zones of the optimum of three species - detritophagous animals of a species Sabatieria (S. pulchra and S. finitima) are very close. Nematodes of these species occur on small depths both on pelit and on alevrit sediments and are euryhaline. The separation of ecological niches of these species is explained by different positions in the sediments along the redox-gradient. The third species, S. palmaris, has an ecological niche distinguished from the two previous ones. It is stenohaline, prefers pelit sediments with a high contents of organic matter.
Far East State University, 8 Sukhanova St., 690000, Vladivostok, Russia. Tel. (4232) 257779, Fax.: (4132) 257200, Е-mail: eco@pin.dvgu. ru

L.I. GRUZDEVA, T.E. KOVALENKO, E.M. MATVEEVA & G.N. LAY.
Influence of heavy metals on the soil nematode populations.
Heavy metals are considered as pollutants of natural biotopes. Soil samples were collected from the heavy-metal-contaminated sites 5, 16, 22 27 km from the ore-dressing mill (Kostomuksha, Karelia). Simultaneously, laboratory experiments were carried out for growing model nematode objects on soil extracts from the contaminated sites mentioned above; and for growing nematodes on the nutrient medium with the addition of increasing doses of heavy metal salts (lead and zinc). We revealed a correlation between the Pb⁺¹ concentration and the nematode abundance in the natural biotope soils (R²=0.63). No correlation was recorded for Zn⁺²concentration. The increase in the abundance of nematode populations under laboratory conditions corresponded to the location of contaminated sites in the natural biotopes at the following distances from plant: 27>22>5>16 km. It accounted for 56, 49, 42, 16 % compared with the control (agar “Difco” without soil extract, 100 %). A significant decrease (P< 0.05) in the nematode number was observed when various doses of heavy metals were added to the nutrient medium (Pb - from 0.3 to 5 mg/l, Zn - 3 to 50 mg/l; variant - 12; replicates -25). Nematode culturing in the medium with high Pb and Zn concentrations lead to a drop in the nematode body size and biomass. Support: RFBR: grant 98-04-48487.
Institute of Biology, Karelian Research Centre, Russian Academy of Sciences, Pushkinskaya str. 11, Petrozavodsk, 185610, Karelia, tel.: (8142)77 36 22, fax: (8142) 77 98 10, E-mail: gruzdeva@post.krc.karelia.ru

B.V. ROMASHOV & V.A. SEMEONOV.
The nematodes-capillariids (Nematoda, Capillariidae) - parasites in semiaquatic mammals.
In semiaquatic mammals is registered 15 species the nematodes of the family Capillariidae. We found two polyspecific species of Capillariidae: Capillaria hepatica (Bancroft, 1893) and Capillaria soricicola Yokogava et Nischigori, 1924) in natural populations of semiaquatic mammals on the territory of Voronezh Reserve. These species become localized in liver parenchyma of hosts and they are greatly pathogenic parasites. Rodents are definitive hosts of C. hepatica. Red mouse (Clethrionomys glareolus) is a dominant on the prevalence of parasite - 47,5% and its abundance - 0,7 (P<0,01). Thus red mouse plays the main part in accumulation and spreading of C. hepatica in the environment. Semiaquatic rodents (European beaver) become the member of the parasitic system because high level concentration of infected eggs of C. hepatica in wetland. At present the infection of Voronezh beaver population by C. hepatica is 19,6%. This index is 50% in some micropopulations. It is determined that the pathology which was caused by C. hepatica reduces biological productivity of beaver populations (micro-populations) on 10-12%. C. soricicola is the parasite of insectivorous mammals. C. soricicola was discovered in Sorex araneus (infection extensivity is 6,5%, abundance - 0,1) and in Neomys fodiens (infection extensivity is 13,5%, abudance - 0,7). High number of S. araneus are the main conditions of functional stability of C. soricicola parasitic system. The high pathogenicity of C. soricicola for definitive hosts on organismic and populational levels is evolutionary conditioned. Because of coincidence of ecological niche of S. araneus and N. fodiens, C. soricicola can be one of the main biotic factors influenced on the population dynamics of semiaquatic insectivorous.
Voronezh Biosphere Reserve, Voronezh, 394080, Russia, E-mail: Voronezh.reserve@,p70.fl6.n5025.z2.fidonet.org

I.A. SKALSKAYA & V.G. GAGARIN.
Periphyton nematodes of polluted bodies of water.
Data on species composition and density of periphyton nematodes are given for three water bodies: Rybinsk and Gorkiy reservoirs and the Latka River - an affluent of the Rybinsk reservoir. Number of nematodes increases significantly mainly due to Diplogasterida in sites of heated water discharged from power stations and domestic and industrial sewages.
Institute of Inland Waters Biology, Borok, Jaroslavl region, 152742, Russia, tel.:(085)4721131508,fax:(085)2253845, E-mail: gagarin@ibiw.jaroslavl.su

N.I. SUMENKOVA & T.M. GENNADIEVA.
Biocenotic interrelations between nematodes and thermophilic bacteria in the process of cultivated mushroom compost fermentation.
The process of spontaneous fermentation directed at alterations of organic material to favorable for cultivated mushroom development, has been shown to take place under the influence of mass multiplication of thermophilic bacteria, basic organic material destructors. Abundance of bacteria is associated with growth of microbivorous-nematode numbers which distribution in compost clamp correlates with the rate of fermentation intensity in its different areas (sections). There is observed intensive fermentation in surface clamp layers under excessive aeration and at optimal temperatures for microorganisms vital activity (20-30⁰ C); nematode numbers are likely to vary within 1000 to 61000 per 10 g. When moved to deeper layers, the temperature is being increased (till 60-75⁰ C in the middle) and oxygen content lessened (practically to anaerobic condition in the center). Accordingly, the intensity of fermentation processes and nematode population density are observed to decrease significantly to total absence in clamp nucleus. Nematode community development is thought to follow the succession pattern which is easily recognized by successive replacement and ecological vicariation of dominant species (for example, Tricephalobus steineri is ousted by Rhabditella pseudoelongata and so on). Final correlation between nematode species numbers in clamp reflects compost physical characteristics and may serve as one of the indices of its maturity. In accordance with V.N. Beklemishev’s (1970) classification the interaction between nematode and bacteria may be direct topic when bacteria populations perform the functions of conditioners changing physical and chemical conditions in compost material. In addition, microbivorous nematodes have trophic relations with bacteria, thus using the latter as nutrient source; and phoric ones owing to which there is a rapid bacteria distribution in substrate due to extremely active saprobiotic nematodes. Financial support: Russian Foundation for Basic Research (99-04-48332).
Institute of Parasitology, Russian Academy of Sciences, Leninskii prospect, 33, Moscow, 117071, Russia, tel.: (095)9523145, fax: (095)2365217, E-mail: Sonin@GELAN.MSK.SU

A.V. TYUTIN.
Prevalence of parasitic nematodes of the genus Camallanus in perch in tributaries of the large reservoir.
The Rybinsk reservoir (Volga river system) was formed in 1941 and is one of the largest in the world (25.4 км³). A level of infection of perch underyearlings by two species of the genus Camallanus was studied in August-May, 1992-1997. The ratio of C.lacustris to C.truncatus is 1:1. More than 600 specimens of Perca fluviatilis were captured in the mouth sections of 3 small tributary streams of the reservoir. In autumn in a small river Shumarovka (about 20 km) the prevalence of parasites was small (1992- 9.8±2.6%, 1993- 6.9±2.0%). In spring owing to flood migration of hosts a rise in prevalence was registered (20.0±5.7% and 16.4±3.5%). Negative correlation between size of rivers and prevalence of nematodes was established (Sutka, more than 80 km- 21.6±4.8%, Latka, less than 15 km- 37.5±7.6%). Acting through intermediate hosts (Copepoda) temperature is the main factor determining the level of fish infection (warm 1995- 48.2±9.6%, cold 1996- 15.2±5.3%). The original distribution of the parasites in fish samples is regular.
Institute for Biology of Inland Waters, Russian Academy of Sciences, Borok, Yaroslavl region, 152742, Russia, tel. (0852)253845, fax: 70852253845, E-mail: tyutin@ibiw.yaroslavl.su

Biodiversity in Natural Ecosystems

I.Ja. ELIAVA & M.A. KUCHAVA.
Soil inhabiting nematodes of the re-established ecosystems.
Soil nematodes were studied during 11 months, 1995-96 in re-established forest ecosystems near Tbilisi. After felling (forty years ago) the original vegetation was artificially substituted by coniferous trees (in one experimental area - EA) and Amygdalus sp. (the second EA); third EA (no artificial re-establishing influence) has been used as a control. Totally 231 species were found in all EAs, one new species has been described. The studied areas are considered to be the mature ecosystems according to the MI value (Bongers, 1990), species composition and their population structure.
Institute of Zoology, Academy of Sciences, pr. Chavchavadze 31, Tbilisi, 380079, Georgia, tel.: 883-2-22-01-64, 22-33-53, E-mail: nacres@access.sanet.ge

A.S. EROSHENKO & T.V. VOLKOVA.
Nematodes of the wild grass plants of the Russian Far East.
109 species of nematodes found on the 185 species of plants. Spiral nematodes Helicotylenchus and Scutellonema and criconematids (Criconema, Mesocriconema and Ogma) have a wide range of host-plants and may be consider as the dominant species. Helicotylenchus ussuriensis distributed in Primorsky and Khabarovskaya regions and is found on 63 species of host-plants. H. clarkei parasitizes on 30 plant species belonging to different families in Amurskaya, Primorsky and Khabarovsky regions, preferably in the moisture biotopes; H. digonicus - on 21 species of host-plants and is recorded only from the south of Primorsky region in the flooded meadows. Pararotylenchus graminis parasitizes on 25 species of plants, but Poaceae plants are the main hosts. For Criconema varicaudata and Mesocriconema curvatum 25 species of Poaceae and Fabaceae are recorded as the host plants in Primorsky and Amurskaya regions. Ogma allantoideum and O. velutina are often recorded in rhizosphere of Poaceae, Cyperaceae and Fabaceae in natural meadows. Pratylenchus emarginatus prefers Poaceae and Cyperaceae in Primorsky, Amurskaya and Sakhalinskaya regions. Tylenchorhynchus canalis and Amplimerlinius planitierum parasitize mainly on Calamagrostis sp., Phragmitis sp., Miscanthus sp., Triticum sp., these species are often found in the rhizosphere of different fodder grasses in Primorsky region. Cyst-forming nematode Globodera artemisiae (sibling species of PCN) is widely distributed in the Far East of Russia, preferably parasitizing in Artemisia spp.; Heterodera graminis, H riparia, Afenestrata orientale parasitize on Poaceae in Primorsky region, Heterodera humuli - on Urtica sp. in Kamchatskaya region. Anguina agrostis is widespread in all regions. It forms galls on the different species of Poaceae. Subanguina graminophila and S. radicicola distribute on small reed (Calamagrostis langsdorffii) in Primorsky , Khabarovsky and Sakhalinskaya regions and form leaf and root galls, respectively. Anguina moxai forms leaf galls on Artemisia spp. and is widespread in the south of Primorsky region.
Institute of Biology & Soil Science, RAS Far East Branch, 159 Stoletiya str., Vladivostok 690022 Russia, tel.: (4232) 311385, 310410, fax: (4232)310193, E-mail: zoology@ibss.marine.su

A.S. EROSHENKO, T.V. VOLKOVA & I.P. KAZACHENKO.
Biodiversity of the plant nematodes of the Russian Far East.
Database on the variety plant-nematodes for the fauna of Russian Far East consists of 242 species of orders Tylenchida (160), Aphelenchida (67), Dorylaimida (15). Fauna of Primorsky region includes 207 species, Amurskaya region - 91 species, Khabarovsky region - 69 species, Sakhalinskaya region - 31 species and Kamchatskaya region - 32 species. Marked difference of qualitative composition of nematode fauna of Primorsky region comparing with other regions is explained not only by natural conditions, but considerably huge amount of nematological samples from the different biocenoses which have been analyzed. Considerable number of species of plant-nematodes found in Primorsky region from the south to Kamchatskaya region. From 12 known cyst-forming nematodes recorded from the Far East of Russia 5 species are known as cosmopolites. Criconema orientale, Ogma allantoideum, Henicycliophora montana, Mesocriconema curvatum , Gracilacus abietis from criconematins, Geocenamus tenuidens, Merlinius falcatus, M nanus, Nagelus leptus from dolichodorids, Rotylenchus alpinus, R capitatus, Helicotylenchus digonicus, H ussuriensis from the spiral ectoparasites are widespread. Pratylenchoides epacris, P. leiocauda, Pratylenchus emarginatus from the roots endoparasites are known in all regions. 83 species of nematodes register only in Primorsky region The most of them are widespread in the different biotopes on the territory of this region. The most variety of nematode fauna is present on the south of Primorsky region. There are a lot of representatives which typical for the Chinese, Korean and Japanese faunae as well as some taxa belonging to ancient local fauna (genus Afenestrata).
Institute of Biology & Soil Science, RAS Far East Branch, 159 Stoletiya str., Vladivostok 690022 Russia, tel.: (4232) 311385, 310410, fax: (4232)310193, E-mail: zoology@ibss.marine.su

EYUALEM ABEBE¹ & A. COOMANS².
Nematode communities of Lake Tana: ecological considerations.
Free-living nematodes were studied from littoral benthic sediment samples collected in December 1993 and January 1994 from three systematically selected sites (Gelda, Gedero and Zegie) in Lake Tana, Ethiopia. All free-living nematodes extracted were identified to the species level, and communities identified using classification and ordination techniques. The identified communities were then characterized with respect to species composition, biomass, density, diversity, size structure, feeding type and maturity index. Total of 40 species were recorded and five nematode communities identified in L. Tana, viz. Gelda at 0.5m, Gelda at 1.5m, Zegie at 0.5m, Zegie at 1.5m and Gedero. Nematode diversity varied over the different communities and was comparable to that reported in the literature for other oligotrophic and mesotrophic freshwater lakes. Most of the difference in diversity among communities could be explained at the genus level. Within-genus diversity was low. The presence of few dominant species characterized four of the five communities. A strategy in niche partitioning is suggested to be the main driving force behind such a composition. Density and biomass also varied significantly over the five communities, density was in the range 91 x 103-504.7 x 103 and biomass was in the range 0.02-0.33g dry wt/m2 (0.01-0.16gC/m2). Deposit feeders were most dominant in all communities followed by omnivore/predators. Epistrate feeders had the lowest abundance. The two communities in Gelda were composed of smaller species than those communities in Zegie and Gedero, and this is explained by the muddy nature of the sediment in Gelda.¹Bahir Dar Teachers College, Personal P. O. Box 223, Bahir Dar, Ethiopia, E-mail: Eyualem@yahoo.com;²University of Gent, Institute of Zoology, Laboratory for Morphology, Systematics and Ecology, Ledeganckstraat 35, 9000 Ghent, Belgium, E-mail: August.Coomans@rug.ac.be

O.V. Holovachov¹ & A. S. SUSULOVSKY².
On study of cephalobids from Ukraine.
In the total of 320 samples of litter, moss and rotten wood collected in Ukraine (mainly in the Carpathians and the Crimea), 28 cephalobid species are recorded. The following genera are identified: Heterocephalobus (6 species), Cephalobus (3), Eucephalobus (5), Acrobeloides (2), Chiloplacus (2), Zeldia (1), Cervidellus (1), Ypsylonellus (2), Acrobeles (3) и Seleborca (2). The males of twelve species are found, among them are Chiloplacus propinquus and Acrobeles sparsus. Heterocephalobus pauciannulatus, Cephalobus quinilineatus, Eucephalobus cornis, Ypsylonellus devimucronatus, Acrobeles cylindricus, A. sparsus and Seleborca mariannae are recorded in Ukraine for the first time. Taking into account the data cited the Ukrainian cephalobid fauna numbers 43 species. An information on morphology and postembryonal development of a number of species is given.¹ Dept. of Zoology, Faculty of Biology, L’viv State University, Hrushevsky str., 4, L’viv, 290005, Ukraine; Tel. (0322) 794794, 794548, E-mail: museum@ipm.lviv.ua;²State Museum of Natural history, NAS, Teatral’na str., 18, L’viv, 290008, Ukraine, tel.: (0322)728917, E-mail: museum@ipm.lviv.ua

N.N. KHODYREV.
Freshwater nematodes in the south taiga belt.
Studies on ecology and biodiversity of the freshwater nematodes is carried out in Kirov region from 1982. Thirty reservoirs of the river Vyatka basin have been studied and 84 species belonging to 50 genera, 32 families, and 9 orders were revealed. The majority of nematodes are representatives of the orders Enoplida (EN), Dorylaimida (DO), Plectida (PL), and Monhysterida (MH). Common species of water bodies studied are: Tobrilus gracilis, T. helveticus, Tripyla glomerans, Ironus ignavus, I. tenuicaudatus, Dorylaimus stagnalis, Plectus cirratus, P. rhizophilus, P. tenuis, Monhystera stagnalis. M. lemani, M. wangi, Eumonhystera filiformis, E. stagnalis. DO species dominate in rivers, EN ones - in lakes, in water pools there is the balance of both orders. In rivers the number of species of PL and MH is relatively equal, in lakes MH>PL, in water pools PL>MH. Nematodes were revealed in all hydrocenoses studied. Sixty eighth (80,9% ) species were found in meiobenthos, 35 (41,6%) in rhizocenosis, , 20 (23,8%) in periphyton, 9 (10,7%) in psammon. Total density varied from 5 to 1,5 mln specimens/m² and has picks in June and October, with the minimum in February and maximum in October.
Zoology Dept., Vyatka State Pedagogical Institute, Lenina str. 198, Kirov, 610007, E-mail: infak@vspu.kirov.ru

I.A. KRUGLIK.
Fauna of nematodes-xylobiontes of the pine Pinus koraiensis.
Nematode fauna of the pine Pinus koraiensis was investigated in order to discover pathogenic nematodes Bursaphelenchus xylophilus and B. mucronatus as well as other nematodes which are able to be danger for the pine. It was stated quarantine species B. xylophilus was absent in the territory of southern Far East while B. mucronatus was present only in plantation. In addition, 4 species belonging to genus Ditylenchus were revealed during the investigation 3 of them are new to science. Belonging these species to certain ecological groups will have to make clear. Besides that, more than 100 species of nematodes were found, most of them are new to science. Part of them belonging to families Anguinidae and Tylenchidae can be determined as nematodes with specific pathogenic effect on base of morphological attributes. Nematodes with nonspecific pathogenic effect belong to families Neotylenchidae and Aphelenchoididae. Considerable part of species from families: Chambersiellidae, Panagrolaimidae and Cephalobidae are devisaprobionts and nematodes from families: Rhabditidae, Diplogasteridae, Diplogasteroididae and Pseudodiplogasteroididae are typical saprobionts.
Institute of Biology & Soil Science, RAS Far East Branch, 159 Stoletiya str., Vladivostok 690022 Russia, tel.: (4232) 311385, 310410, fax: (4232)310193, E-mail: zoology@ibss.marine.su

L.V. KULANGIEVA & V.V. GALTSOVA.
Nematode biodiversity of Russian Arctic Seas.
We prepared the taxonomic list of species of freeliving nematodes from Russian Arctic seas. It includes about 330 species. Nematofauna of the White, Barents and Kara Seas was studied more complete (131, 215 and 85 species respectively). A few species of nematodes were found in Laptev and East-Sibiran Seas. Chuckchee Sea was not investigated at all. The method proposed by Golikov (1976) was applied for the estimation of the level of the study and biodiversity of nematodes. This method allows to compare the character of the divergence in different taxonomic groups on the basis of quantitative parameters. At first the evaluation of the level of the study for separate groups (Foraminifera, Nematoda, Polychaeta, Gastropoda, Bivalvia) from Russian Arctic Seas was done. Bivalvia was the more complete studied group of invertebrates. The level of their study was 70%. It is possible to find 400 species. The least studied group was freeliving nematodes: 25 per cent and about 1300 species respectively. Thus it is possible to find about 1000 species of freeliving nematodes in Russian Arctic Seas. We could give the evaluation of the expecting number of species for each of six Arctic seas. The level of the study of nematodes for the White, Barents and Kara Seas were done using the same method. As for Laptev, East-Siberian and Chuckchee Seas we used the information about the distribution of species number of model groups which level of study is very high for all seas under study. Support: RFBR (97-04-48129) Biodiversity Program (2.1.63).
Zoological Institute RAS, St.Petersburg 199034, Russia, tel.: 7 812 3281212, fax: 7 812 3282941, E-mail: gvv@eti.mail.iephb.nw.ru

V.O. MOKIEVSKY¹, E.V. SKUKINA² & A.V. TCHESUNOV².
Deep-sea nematodes from Central Arctic Basin taxonomic composition and biodiversity patterns in different scales.
Qualitative samples were collected with multiple corer during expedition ARK XIII/2 on RV POLARSTERN in 1997 on the Yermak plateau and in the Fram strait from the depth of 1 km. Small-scale heterogeneity in abundance of meiobenthos and taxonomic composition of the free-living nematodes were investigated on the square of about 1 m2. Heterogeneity within samples occurs both in total numbers of organisms and in taxonomic composition of nematodes. High rates of diversity are followed by low population density of each species in the samples. Similarity indexes of taxonomic structure within the investigated area are mainly less then 50% and do not correlate with the distance between samples. On the species level, coexistence in scale of centimetres occurs mostly in morphologically distant forms including those which belong to the same genus. Using the data from other deep sea sites, we may conclude that in geographical scale the deep-sea fauna is composed of quite different set of families comparing with sea-shore one. At the same time, taxonomic composition within deep-sea zone shows a high rate of similarity throughout the World Ocean. Some specific morphological characters such as long tails, large amphids with expanded corpus gelatum are peculiar for deep-sea nematodes.¹ P.P. Shirshov Institute of Oceanology Russian Ac. Sci., Moscow 117218, Nakhimovsky prosp., 36, tel (095)124-7996, fax (095)124-5983, E-mail: vadim@ecosys.sio.rssi.ru;²Moscow State University, Faculty of Biology, Dept. of Invertebrate Zoology, Moscow, 119899, Russia, tel (095)939-3656, E-mail: avt@ATchesunov.home.bio.msu.ru

O.N. PAVLYUK.
Nematodes from the Alekseev Bay, Sea of Japan.
The comparative analysis of the species composition and population density of nematodes was made in Alekseev Bay under conditions of the commercial breeding of Mizuhopecten yessoensis (1985) and after the farm was liquidated (1998). In the period of mollusks cultivating showed that in the past culture area with grounds represented by the sine black mud, the population density increased anomalonsly and the species composition became poor. At present it is found that in the central part of Bay, in culture area, composition of grounds changed and silting decreased. The population density of nematodes reduced always 4 times. Nematodes were next to foraminifera in dominance in meiobenthos and took the third place. The species composition of nematodes increased and the change of the dominant species took place. In 1985, Axonolaimus seticaudatus, Eurystomina alekseevi and Anticoma possjetica dominated. In 1998, Ax. seticaudatus remained a dominant species, A. possjetica became no numerous species and E. alekseevi was not found. The species Paramonchystera polerba, Panduripharynx unidentatum, Sabatieria finitima and Enoplolaimus medius dominated. The change of grounds, decrease of population density of nematodes and increase of species composition points to reducing processes occurring in Bay after the liquidation of the mollusk culture farm.
Institute of Marine Biology, Vladivostok, 690041, Russia, tel.: 4232 311 182, fax: 7 4232 310 900, E-mail: inmarbio@mail.primorye.ru

N.G. SERGEEVA.
Free-living nematods in habitats near metane gas seeps (NW of the Black Sea).
The diverse and numerous meiofauna was found in region of situated metane gas seeps ( 77 -232 m depth ) on nine stations. Free-living nematods are dominant (95-98 % total of meiobenthos). In a range of depths 77 - 151 м number of nematods reaches 200 - 500 ind. per 10см^2. Nematods are distributed in the depth of 6сm in bottom sediments, but the maximum concentration of nematods (80 -90 %) is observed in upper 1-сm horizon. The data about species structure of nematods on investigated depths and down a sediment depths of 6 centimeters are received. Specific morphological anomalies of nematods are revealed.
Institute of biology of the southern seas ANU, 335011, Nakhimova av. 2, Sevastopol, Ukraine; tel.: 54 47 85, fax: (0692) 55 78 13; E-mail: sergeeva@iuf.net

A.V. SHOSHIN.
The Baikal Lake nematodes fauna: the present and prospects.
Baikalian nematodes variety is amazing. At the moment 53 species nematodes from the lake is described, only 6 are widespread. The author’s Southern Baikal collection is contained about 300 species, main part species are new. Tobrilids are the most diverse. Probably, they were pioneers in prabaikalian lakes; their evolution went on a way of development of diverse ecological niches of the huge lake. Bunch endemic tobrilids new genus is supposed to be described in a short time. All of them are united by curious evolutionary transformations of the head and stoma. The fauna baikalian monhysterids has appeared unexpectedly rich. The genus Hofmaenneria representatives are especially diverse; whose variety concedes only baikalian tobrilids. As well as tobrilids, baikalian hofmaennerids could adapt to various types of nutrition. Another rich groups are genus’s Eumonhystera and Penzancia. A variety of nematodes-commensals from oligochets belonging to the genus Domorganus is surprisingly great. Research baikalian nematodes is interesting from the point of view of study morphology and systematic of some groups of freshwater nematodes, the fauna origin of the unique lake, theory of evolution. The variety baikalian nematodes is so great, that only diversity researches will require efforts not one generation of nematologists.
Institute of Ecology of the Volga River Basin, ul. Komzina 10,Togliatti, 445 003, Russia, tel.: (8469) 48 94 97, E-mail: star@infopac.ru

G.B. SULTANALIEVA.
Free living and parasitic nematodes in Kyrghyzstan.
Representatives of 363 species of free-living and plant parasitic nematodes were reported in Kyrghyzstan. Among these, 23 species described as new to science. The species of nemathodes were revealed belong to 9 orders, 61 families, and 133 genera. The order Tylenchida is represented by 12 families, 32 genera and 100 species (27,6%); the order Aphelenchida - 3 families, 4 genera, 43 species (11,8%); the order Dorylaimida - 14 families, 22 genera, 66 species (18,2%); the order Enoplida - 9 families, 13 genera, 27 species (7,4%); the order Areolaimida - 7 families, 14 genera, 23 species (6,3%); the order Monchisterida - 3 families, 9 genera, 15 species (4,1%); the order Chromadorida - 5 families, 11 genera, 13 species (3,6%); the order Mononchida - 2 families, 5 genera, 11 species (3,1%).Nematological investigations began in Kyrghystan only since 1962 years. There is investigated fauna of the nematods in water ecosystems, agricultural and forest plants, and the soils of different ecosystems in Issyk-Kul depression - from stone strewn deserts to sub-alpine and alpine meadows.
Institute of Biology and Pedology Kyrgyz National Acad. Sci., Tchui Avenue 265, Bishkek, Kyrgyzstan, Tel. (996-312) 255370.

M. VINCX, G. DE SMET, A. VANREUSEL, S. VANHOVE, J. VANAVERBEKE & M. STEYAERT.
NEMAS, a database for free-living marine nematodes.
(Presented by N. Smol).
The ‘NEMAS’ database has been created as an instrument to the scientific community for taxonomic, systematic, phylogenetic and ecological purposes. The aim is to promote biodiversity studies and to improve and stimulate identification quality control. The database contents a complete list of all species of free-living marine nematodes described, organised in the most recent systematic approach. It links to whatever kind of information (documents, video, internet, reports, slides, …). Queries are possible over all fields. The advantages of this database are explained. At this moment the database is completed for Antarctic nematodes and is published as a CD-ROM, which will be demonstrated. By the end of December 2000 a CD-ROM with information about all free-living marine nematodes will be published and the fully searchable database will be free on Internet.
Marine Biology section, Zoology Institute, K.L. Ledeganckstraat 35, 9000 Gent, Belgium, tel.: 32-9-264.52.10, fax: 32-9-264.53.44, E-mail: magda.vincx@rug.ac.be

Biodiversity in Agricultural Ecosystems

L. JURAEVA.
Fauna of parasitic nematodes of vegetable crops of Tajikistan.
For the first time fauna of parasitic nematodes wsas studied on vegetable crops. During 1994-1998 new information about hearth and harm of 52 species of nematodes, 9 of which have been registered before, was collected in vegetable-growing farms located in three geographical-territorial zones of Tajikistan (Ivanova & Semikolenova, 1967; Juraeva, 1983).Roots and soil of tomatoes, cabbage, cucumbers, carrot, pepper, beet, garlic, and egg-plants were investigated for contamination by local parasitic nematodes. 26 species were registered for the first time in the natural life in southern areas of the country. Almost in all vegetable-growing farms the following species were revealed: Ditylenchus dipsaci, Pratylenchus vulnus, P.pratensis, Xiphinema vuittenezi, X.index, Rotylenchus globratus, Longidorus africanus, Nagelus macrodorus. In the central area - 19 species and usually in sampus were distinguihed X X.index, X.pachtaicum, L.tardicauda, P.thonei, Helicotylenchus digitiformis, H.kralli, Criconemella annulata, C.xenoplax. In the norhen area 15 species were discovered with dominated species of Helicotylenchus diconicus, H.multicinctus, Tylenchorhynchus dubius, P.vulnus, Xiphinema pachtaicum.. In general, the species of phyto-parasitis are presented by 2 orders, 9 families, and 16 genera. 13 species have turned out to be common for studied cultures. The difference in fauna of nematodes of vegetable crops is connected with natural-climatic conditions in which farms are situated.
Institute of Zoology & Parasitology, Academy of Sciencies, Sherosi Av. 29, ap. 128, Dushanbe 734043 Tadjikistan, tel.: 35-57-52, E-mail: Luba@academy.td.silk.org

A.J. MEYER.
Plant parasitic nematodes in deciduous fruit orchards and vineyards in the Western Cape Province of South Africa.
Between 120 000 and 150 000 hectares are planted to a variety of pome-fruits, stone-fruits and vines in the Western Cape Region of South Africa. This region has a mediterranean climate with winter rainfall, in contrast to the rest of the country which experiences summer rainfall. In addition to the insect pests and diseases affecting production in this region, growers and researchers recently have had to add the often overlooked damage caused by plant parasitic nematodes. Stone-fruits are damaged by Meloidogyne species, Mesocriconema xenoplax, and Xiphinema species. Apples are free of root-knot nematodes but may be affected by Pratylenchus species and Xiphinema brevicolle. Vines suffer from fanleaf transmitted by Xiphinema index and are further infected by very much the same parasites that damage peach and plum trees.
Department of Entomology and Nematology, University of Stellenbosch, Private bag x1, Matieland 7602, Republic of South Africa: tel.: +2721 8084777, fax: +2721 8084336, E-mail: AJM@MATIES.SUN.AC.ZA

A.A. SHESTEPEROV.
Plant damages caused by phytonematodes in Russia.
Recent reforms of economics in Russia led to deep changes of agricultural practice. It caused the increase of damages caused by plant pathogens including phytonematodes of potatoes, tomatoes (Globodera spp., Ditylenchus and Trichodorus spp.), soybean (Heterodera trifolii), sugar beet (H. schachtii), cereals (Bidera spp.), onions, garlic, strawberry (Ditylenchus dipsaci), vegetables in glasshouse (Meloidogyne spp.) and fruit tries (Pratylenchus penetrans). The forecast based on trend of present changes points out a further increase of nematode damage, including new appearance of some other species like Aguina tritici (wheat), Hexatylus spp. (potato), and Aphelenchoides ritzemabosi (black currant) and further spreading of Globodera rostochiensis, M. chitwoodi, Ditylenchus dipsaci.
All-Russian Institute of Helmintology, B. Cheremushkinskaya 28, Moscow 117259, tel: (095) 124 86 66.

Nematology: Teaching and Organisation

N. SMOL.
An overview of teaching courses in Nematology, with special reference to the PINC of the University of Gent, Belgium.
An overview is presented of Nematology training courses worldwide, comparing their duration, period, target audience, objectives, programme, admission requirements and available grants for participants. The benefits, distribution, follow-up, requirements and drawbacks of Nematology courses are discussed, emphasizing their potential importance in preserving and distributing current knowledge within a rapidly changing scientific environment. While a number of short-term training courses exist, the Postgraduate International Nematology Course (PINC) of the University of Gent is unique in its one-year duration and in dealing equally with plant parasitic, free-living and entomopathogenic nematodes. Participants who successfully pass exams and complete a personal research project are awarded the degree of ‘Master of Science in Nematology’. The programme, academic staff and selected graduates of PINC are briefly presented.
Nematology Course, Zoology Institute, K.L. Ledeganckstraat 35, 9000 Gent, Belgium, tel: 32-9-264.52.16, fax: 32-9-264.53.44, E-mail: nic.smol@rug.ac.be

X. GAO.
Introduction to Plant Nematology in China.
Fundamental and applied plant nematology in China have developed progressively in the 20th century. In sustainable and subsistence farming and forestry systems in the country, the problems of plant diseases caused by plant parasitic nematodes have become increasingly important in the past twenty years. The understanding and management of these nematodes is the responsibility and challenge of the plant nematologists today and in the future. This review examines certain aspects of plant nematology in China including: 1) An outline of the history, 2) organizations, 3) main academic achievements, 4) future prospects. Support: the National Natural Science Foundation & the Natural Science Foundation of Guangdong province.
Laboratory of Plant Nematology, South China Agricultural University, Guangzhou, 510642, P R China, tel: 0086 20 85511299 ext. 3133, fax: 0086 20 85511393, E-mail: xbgao@scau.edu.cn

AGRICULTURAL NEMATOLOGY

MANAGEMENT & CONTROL: FIELD AND LABORATORY STUDIES

E.M. Aslanyan¹, G.B. FEDOROVA², S.G. Besayeva¹, N.N. Galkina¹, A.A. Mikhailov¹ & G.S. KATRUKHA².
A search of promising actinomycetes for control of nematodes.
The effective methods of plant protection may be developed on the basis of actinomycetes which synthesize substances of different composition and structure with expressed pesticide properties. The biopreparations received have advantages in comparison with chemical preparations because of their specific action and ecological safety. However, the number of the nematocide preparations is limited as against large number of fungicides and insecticides. So, it is important to search new preparations. We have directly searched new isolates of actinomycetes possessed nematocide effect. Previously selected cultures have been indicated as Streptomyces, Micromonospora, Actinomadura. The experiments have been conducted on young nematodes' larvae of Caenorhabditis elegans. During preliminary screening four most active isolates (# 35, 119, 132, 153) have been selected among 300 ones by preliminary screening. The pesticide properties of the selected isolates are defined as biologically active substances (BAS). Physico-chemical analysis of BAS with the use of cultural liquid extract have been conducted as well as concentration and purification of some components using thin layer chromatography (TLC), electrophoresis, UV-, IR- and MS- spectrometry methods. The obtained concentrates of mycelium and supernatant of four isolates have been examined on nematocide activity. 10% and 50% solutions of the concentrates have been used under experiments. The total mortality of nematodes has been registered for the strain `119 ( 50% solution of mycelium). The rest isolates have not shown mycelium activity. The concentrates from supernatant have shown higher nematocide activity. 10% solutions of the isolates # 35, 119,153 have caused 100% death of nematodes. The isolate # 132 has shown 100% mortality of nematodes when 50% concentrations have been used.¹The State Scientific Center of Applied Microbiology, Obolensk, RF;²Institute of New Antibiotics RAMS, B. Pirogovskaya, 11, Moscov, RF, tel.: (095) 246-6983; fax: (095) 245-0295; E-mail: instna@online.ru

S. KAZLAUSKAITE.
Dynamics of nematode complex density in barley during vegetation.
Experiments were carried out in the fields of Experimental station of the Lithuanian Agricultural University, where cereals were grown in the light loam soil in conditions of sustainable agriculture and cereal rotation of four fields: 1. Barley; 2. Oat and vetch mixture; 3. Wheat; 4. Oat. Goal of experiments is to determine how complex of nematodes changes if cereals grow in the field every year. Ten samples (total 200 g of soil and roots) are taken along diagonals, then mixed and 10 samples of 5 cm³ of soil and 10 samples of 2 g of roots were taken. Nematodes were extracted using modified Baerman method. Summarized density of nematodes decreases during bushing out period, increasing at the finish of the barley vegetation.
Lithuanian Agicultural University, Department of Plant Protection, Kaunas, Lithuania.

J. KIMPINSKI, W.J. ARSENAULT & J.B. SANDERSON.
Management of Pratylenchus spp. and bacteria-feeding nematodes by crop sequences.
Populations of root lesion nematodes (primarily Pratylenchus penetrans) and bacteria-feeding nematodes (tentatively identified as mostly Diplogaster lheritieri) were monitored in marigold (Tagetes erecta L. cv. Nemanon and T. tenuifolia Cav. cv. Nemakill), mustard (Brassica juncea Coss. cv. Domo), annual ryegrass (Lolium multiflorum Lam. cv. Lemtal), red clover (Trifolium pratense L. cv. Marino Red) and soybean (Glycine max Merr. cv. Proteus), and in subsequent potato (Solanum tuberosum L. cv. Superior) crops. The data were combined and averaged over a three-year period from three sites. Samples taken in late September indicated that the marigold cultivars had the lowest root lesion nematode levels at 750/kg of soil and 180/g of root, while soybean had the highest levels with 5310/kg of soil and 4580/g of root. Root lesion nematode levels in late September at harvest in potato grown after marigold were 850/kg of soil and 920/g of root, while the levels in potato grown after soybean were 2660/kg of soil and 1850/g of root. The remaining cover crops and subsequent potato crops generally had root lesion nematode levels that were intermediate between the marigold-potato and soybean-potato sequences. In one case, the root lesion nematode level was 2540/g in roots of potato following red clover. The population levels of bacteria-feeding nematodes in rhizosphere soil did not differ significantly between the cover crops (mean of 6200/kg), nor in the subsequent potato crops (mean of 4400/kg). Tuber yields in potato crops following marigold, annual ryegrass, mustard, soybean, and red clover were 43.8 t/ha, 42.3 t/ha, 42.0 t/ha, 40.7 t/ha, and 39.2 t/ha, respectively.
Agriculture and Agri-Food Canada, Crops and Livestock Research Centre, P.O. Box 1210, Charlottetown, Prince Edward Island, C1A 7M8, Canada, tel.: 1-902-566-6837, fax: 1-902-566-6821, E-mail: kimpinskij@em.agr.ca

E.N. ROMANENKO¹, N.D. ROMANENKO² & N.I. KOZIREVA².
Comparative valuation of nematicidal activity of biopreparation - rizoplan and biostimulator - immunocitophit after preplanting potatoes processing.
Testing of nematicidal activity of biopreparation "rizoplan" (obtained on the base of active strain of antagonistic bacteria Pseudomonas fluorescens) and biostimulator "immunocitophyt" (mixture of ethyl's ether of arachidonic acid and uric acid) was carried out in the field test. The former carries out plant protection by directly suppressing phytopathogenic fungi, bacteria and nematodes, the other - by the stimulation of protective mechanisms of plants, including reduction of the sterol, which are necessary for nematodes and production of toxic for them phytoalexins. Soil samples were taken immediately until planting processed and unprocessed potato and every 2 and 3,5 mounths ofter planting. In the first two months rizoplan supressed significantly numbers of all nematode trophic groups, specially bacterio-, mico- and phytophages, where as immunocitophyt was greatly conductive to disappearace only phytophagous nematodes. In 3,5 months after planting immunocitophyt preserved its nematicidal activity, but there was an incrising of phytopathogenic nematodes and other trophic nematode groups in rizoshere of potato plants, processed by rizoplan.¹A.N. Bach Institute of Biochemestry RAS, Leninskii prospect, 33, 117071, Moscow;²Institute of Parasitology RAS, Leninskii prospect, 33, 117071, Moscow, tel.: 095 9523145, E-mail: ran@edunet.ru

S.G. STOREY.
A Nematode Advisory Service in South Africa.
The establishment of a commercial, privately-owned advisory service to serve the producers in the Western Cape area of South Africa is discussed. The Mediterranean climate, different soil types, and varying topography results in many different crops being grown in the area. The various important crops are discussed as well as the importance of the different nematode genera on each crop. Mention is also made of some of the less important crops and their nematode profiles. Special reference is made to the change in the agricultural focus in the "new South Africa". Various problems relating to sampling, logistics, extraction methods, lackof knowledge and recommendations to producers are reviewed.
Nemlab, P O Box 2825, Durbanville, South Africa, 7551, tel.: +(21) 9752350, fax: +(21) 965006, E-mail: storey@intekom.co.za

Root Knot Nematodes of the Genus Meloidogyne

O.V. BOLTOVSKAYA & D.D. SIGAREVA.
Biological methods of control of the quantity of rootknot nematodes on vegetable species in greenhouses.
In 1997-1998 twenty greenhouse farms (GF) were examined in Kiev, Cherkasse, Odessa, Vinnitsa, Zaporosge, Hmelnitsk, and Symskaya regions (total area 217 sq. hectares). In 15 GFs (164 hectors) infections of cucumbers and tomato plants by rootknot nematodes Meloidogyne incognita (Chitwood) were revealed. The degree of root system infection (Schmidt scale) was 3 to 4 marks in the middle of vegetation and 4 to 5 marks at the end of vegetation period. Yield losses were averaged 27 to 39 %, in some cases the death of the plants occured prior to the fruit formation. Hitozane, trihodermine, immunotsitafit wre studied to control the rootknot nematodes density. Trihodermine application in concentration of 2.5 and 5 gm/plant, hitozane in concentration of 200 ml/plant, and immunotsitafit in .06 gm/plant showed favorable results. Their effectiveness corresponded to 51.7, 61.3, 67.3, 43.8% at 1-2 mark rootknot formation levels.
Institute of Plant Protection, Ukrainian Academy of Agrarian Sciences, Vasilcovskaya st. 33, Kiev, 252022, Ukraine, tel.: (044) 2631124, fax.: (044) 2632185, E-mail: nikol@mail.kar.net

L.A. GUSKOVA¹, V.M. MOTOV² & V.A. SHVEDOV³.
Resistance tomato hybrids to root-knot nematodes.
“Agrosemtoms” company has prepared some new tomato hybrids for greenhouses in north and subtropic (middle) regions: Adonis, Vikont, Vyatich, Gunin, Siver, Ruso, Kupec, Palladin, Flamingo with complex resistant to VTM, Fusarium sp., Cladosporium sp., Verticillium sp. The goal of our investigation is to determine resistance of hybrids to populations of Meloidogyne incognita (race 1) and M. javanica. Appraisal of hybrids put through 10 variants of the vegetation experiences of 1997-98. Every tomato seedling (two leaves) was inoculated with 250 juveniles. After two month the root infection was tested using root knots number (Taylor-Sasser scale) in comparison with resistant varieties - Dombello (resistant to M. incognita) and Vaynmon (resistant to M. javanica) and susceptible varieties Energo and Krasnaya Strela. Level of resistance of each hybrid has been characterized by the mean infection value, indicies of infection and susseptibility. It was concluded that Vikont, Vyatich, Gunin, Cupec, Flamingo are highly resistant to M. javanica and M. incognita. Hybrid Palladin is “average resistant”, and Adonis only “resistant”. These hybrids are the most significant ones because both nematode species co-exist in greenhouses.¹All-Russian Plant Protection Institute Russia, Podbelskogo shosse, 3, St.-Petersburg - Pushkin, 189620, , tel./fax: (+7-812) 470-4384, E-mail: vizr_spb@spb.cityline.ru;²Company “Agrosemtoms”, Lenina st., 101, Kirov, 610002, Russia, tel.: (+7-8332) 67-02-68, fax: (+7-8332) 25-5142; ³Saint-Petersburg State of Agricultural University, Peterburgskoe shosse 2, St.-Petersburg - Pushkin, 189620, tel./fax: (+7-812) 470-0429

D.G. KIM¹, J.K. LEE²& S.B. LEE².
Population dynamics and distribution of root-knot nematodes under intensive greenhouse cultivation system.
Oriental melon (Cucumis melo L. var. Makuwa) grafted on Shintozoa (Cucurbita maxima X Cu. moschata) was planted at Jan. 20 during the winter month in Korea under plastic-covered soil in a greenhouse. Seven months after, horizontal and vertical distribution of root system and juveniles (J2) of Meloidogyne sp. were examined. The highest nematode density was 107 J2/g soil. J2 distributed 10%, 24%, 22%, 17%, 19%, 7%, and 2% at the depth of 0-5cm, 6-10cm, 11-15cm, 16-20cm, 21-25cm, 26-30cm, and 31-35cm, respectively. Nematode distribution was relatively uniform horizontally, while root mass was compacted around the center.¹Songju Fruit Veg. Exp. Sta., Kyongbuk Agr. Tech. Admin., Korea, tel: (+82-544) 9316789, fax: (+82-544)9311753, E-mail: kimdgkr@chollian.net;²Agr. Sci. & Tech. Inst., Rural Dev. Admin., Korea, tel: (+82-331)2900473, fax: (+82-331)2900403, E-mail: jklee@niast.go.kr

V.V. KOTOVA¹ & E.G. COZARI².
Phytocontrol of Meloidogyne in glasshouse.
Phytocontrol technology included an intercrop cultivation of water cress and application of water cress-based compounds in hot spots of Meloidogyne and root-rot. Phytocontrol-based technology was more effective during tomato and cucumber growing than application of Vidat®. Biological effect of Phytocontrol was over 80%. Phytocontrol reduced plant losses in 2.4 folds, occurrence of Meloidogyne and root-rot respectively in 2.2 and 12.1 folds. Plant growth was stimulated, yield increased by 0.7 kg/sq.m in average. First appearance of symptoms caused by Meloidogyne on plants treated by water cress compounds was some 2 months later than after Vidat® treatment.¹Russian University of People`s Friendship, Miklukho-Maklaya 8, Moscow.² All-Russian Research Institute of Vegetable Breeding and Seed Production, Lesnoy Gorodok, Moscow region, 143080, Russia, E-mail: vniissok@cea.ru

H. MOCHIDA¹ & T. KOBAYASHI².
Preceding crop suitable for sweetpotato production estimating from nematode damage.
Growth and yield of succeeding sweet potato as influenced by preceding crops have been studied for three years. Much yield is gained when radish, Italian ryegrass, peanut and guineagrass are cultivated as preceding crop of sweetpotato due to high harvest index . In the case of potato and cabbage low yield is resulted due to low harvest index. The nematodes density is higher at the sites after harvesting potato and cabbage than at the sites after harvesting other crops, particularly for Meloidogyne incognita. The most yield is gained for both varieties when Italian ryegrass is cultivated as preceding crop. Much amount of potassium is contained in the soil compared to nitrate after harvesting Italian ryegrass . Potassium is very important element for the enlargement of tuberous root. And it is said that much amount of potassium content reduces nematodes damage.
Kyushu National Agricultural Experiment Station, Miyakonojo, 8850091, Japan, tel:0986(22)1506, fax: 0986(23)1168, E-mail:
¹mochidah@mykz.affrc.go.jp,²thor@mykz.affrc.go.jp

Z. SANO.
Histological responses on leguminous enemy plants to the infection of Meloidogyne incognita.
Some leguminous plants, such as Arachis hypogea, Crotalaria spectabilis and Macroptilium atropurpureum, effectively suppressed population densities of Meloidogyne incognita. To examine their suppressive effects, development of the nematode and the histological changes in the roots of those plants were observed. In both M. atropurpureum and C. spectabilis giant cells were induced. In M. atropurpureum however the cytoplasm was vacuolated and the thickening of the cell wall was moderate even 13 days after inoculation of the nematodes. Two thirds of these cells degenerated within 23 days after inoculation. In the roots of M. atropurpureum only a few juveniles developed immature small ovaries, but none of them developed beyond the second stage and eventually some degenerated within 33 days after inoculation. In C. spectabilis the infecting juveniles were enlarged moderately though developed small genital primordia that remained sexually undifferentiated in spite of the formation of developed giant cells which persisted until 35 days. Necrosis was sometimes observed as well. In the A. hypogaea roots, most of the juveniles were observed outside of the central cylinders within 2 mm from the root tips and they did not develop at all. Necrotic and empty cells were always observed in contact with those juveniles and along the tracks of penetration.
Dep. of Pest Control, Kyushu National Agricultural Experiment Station, Nishigoshi, Kumamoto, 861-1192, Japan; tel.: 81 096 242 1150, fax: 81 096 249 1002, E-mail: sanoz@knaes.affrc.go.jp

M.C. de A.V. SANTOS, I.M. de O. ABRANTES & M.S.N. de A. SANTOS.
Esterase phenotypes of Portuguese populations of root-knot nematodes, Meloidogyne spp.
Nonspecific esterases of 1-5 females from 35 root-knot nematode populations from Continental Portugal and S. Miguel, Azores were analysed by electrophoresis in vertical thin-slab polyacrylamide gels. In order to facilitate comparisons of esterase phenotypes between gels, an M. javanica extract was included, in all gels, as a reference. Eleven major bands of esterase activity were detected and five esterase electrophoretic phenotypes were resolved. Only one of the populations exhibited three distinct esterase phenotypes: J3 (M. javanica); I1 (M. incognita); and S2‑M1 (M. hispanica). Of the remaining populations 50% presented phenotype I1 (M. incognita), 23,5% H1 (M. hapla), 20,6% J3 (M. javanica) and 5,9% A3 (M. arenaria). Phenotype H1 was the most prevalent in Continental Portugal whereas I1 was resolved in all, except one, S. Miguel populations. Nonspecific esterase banding patterns allowed separation of all five species and has been helpful in resolving difficulties with morphological similarities.
Departamento de Zoologia and Instituto do Ambiente e Vida, Universidade de Coimbra 3004-517 Coimbra, Portugal, tel: (39) 834729, fax: (39) 826811, E-mail: nemz@zoo.uc.pt

B. WANG & X. GAO.
Attachment dynamics of Pasteuria penetrans on three species of Meloidogyne.
Pasteuria penetrans has been demonstrated as a potentially important biocontrol agent of plant nematodes. The attachment of endospores to the cuticle of nematodes is one of the most important steps for its pathogenisity. The attachment of an isolate originally from South Africa designated Pp3 of Pasteuria penetrans to juveniles (J2) of three common species of Meloidogyne in China was evaluated in vitro. The ability of the endospores to attach was evaluated on freshly hatched juveniles in aqueous suspensions of 103, 104, 105 endospores/ml in every 24 hours in a period of 72 hours. Pp3 was adhesive to the juveniles of M. javanica, M. incognita and M. arenaria. There were significant differences in spore attachment among the three species. Pp3 was the most effective in attaching the cuticle of M. javanica. The second was M. incognita, and M. arenaria was the most ineffective one. In addition, the attachment dynamics of Pp3 on M. javanica was evaluated in every 4 hours in a period of 80 hours, the time was found to be an important factor to influence the attachment. The number of attached spores increased gradually. But after the number of attached spores reached 16.0 per juvenile in 44 hours, the attaching speed was reduced. In the former 44 hours the number of attaching speed was 0.364/ J2 each hour, in the later 36 hours, only 0.074/ J2 each hour. This result suggests that there are probably attachment sensitive localities on the cuticle of juveniles of the nematodes. Support: the National Natural Science Foundation, Foundations of Ministry of Education & the Natural Science Foundation of Guangdong province.
Laboratory of Plant Nematology, South China Agricultural University, Guangzhou, 510642, P R China, tel: 0086 20 85511299 ext 3133, fax: 0086 20 85511393, E-mail: xbgao@scau.edu.cn

V. Zinovieva¹ , N.I. Vasyukova², L.I. Iliinskaya², N.G. Gerasimova², E.A. Perekhod², Zh. Udalova¹ & O.L. Ozeretskovskaya².
Modulation of tomato resistance to plant nematodes by biogenic elicitors.
In present investigation the mechanisms of induced tomato plant resistance to root-knot nematode were studied. Biogenic elicitors - arachidonic acid (AA), salicylic acid (SA), methyl ether of jasmonic acid (MeJA) were shown to stimulate the growth and weight of tomato plants infected by Meloidogyne incognita. The treatment of tomato seeds with AA (10 ^-6 - 10^-7 M) significantly suppressed the number of galls and eggs produced and increased duration of nematode development. SA( 7x 10 ^-7- 7x10^-8 M) and MeJA ( 10^-7M -10^-4M ) had no protective effect against M. incognita, but the compositions of SA (7x10^-8M) + AA ( 10^-10 M) and MeJA (10^-7 M) + AA ( 10^-10 M) significantly induced resistance of tomato plants to nematode. These mixtures caused changes in composition and content of free sterols and thereby immunostimulation effect in plants. It is shown that AA and MeJA increased the activity of lipoxygenase in leaves of tomato , the roots of which were inoculated with M.incognita. The data obtained suggest that the mechanisms natural and induced by biogenic elicitors tomato resistance to the nematode have the same origin. (RFBR grants 97-04-48629 and 99-04-48332).¹Institute of Parasitology RAS, Leninskii pr.33., Moscow, 117071, Russia, tel.: (095) 9544034, E-mail: olga.k@g23.relcom.ru;²A.N.Bach Institute Biochemistry RAS, Leninskii pr. 33., Moscow ,117071, Russia.

PCN and Other Cyst-Forming Nematodes

V.A. BYKOVSKI & POLOVINKO G.G.
Quarantine control of Globodera rostochiensis on potatoes.
Globodera rostochiensis was found to be the reason of recent outbreaks of disease on potato fields in two villages of Karachaevo-Cherkeskaya Republics, Russian Federation. Nematode belongs to pathotype R01, as it was established on reaction of "signal" plants. Nematode cyst density varied from 1 to cyst per probe on fields planted with different cultivars of potato. Plants of cv. Nevskii carried less cysts and adult nematodes than plants of local varieties. Cysts density in soil was significantly decreased under nematode-resistant cultivars Cardinal and Progozhii-2. Besides growing nematode resistant potato, crop rotation, thermal and chemical treatment were applied to reduce the nematode population.
State Quarantine Inspection on Karachaevo-Cherkesskaya Republic, Cherkessk, 357000, Russian Federation.

M. DAMADZADEH & B. ANSARIPOOR.
Study of identification and distribution of cereal cyst nematode in Esfahan area of Iran.
During this study 231 soil and root samples from different wheat and barley fields of different areas of Esfahan province were taken. In the laboratory by Fenwick can technique the cysts of 200 gr. soil sample were extracted and determined where they are in Heterodera group or not. In 113 of soil samples cysts were seen (48.8%) and of those only in 46 samples (20%) the cysts of H. avenae group were identified. From the fields of these areas further samples during growing period of crop were taken and fresh cysts on roots were seen. Also in the laboratory the cone‑top of identified cysts were made and the 2nd stage juveniles of these cysts were extracted and permanent slides were made. Using Mulvey & Golden(1983) and Wouts et al.(1995) keys the morphologic and morfometric characters were compared. According to the presence of underbridge (not distinct in some samples), the vulval slit (9.4),stylet length (24-25) and tail length (53.6-64.4) in the 2nd stage juveniles the Heterodera filipjevi was identified. Population density was 16(1-153) cysts/200g soil.
Agricultural Research Center, P.O.Box 81785-199, Esfahan, Iran, tel.: 031687221, fax: 031-759007, E-mail: agresor@cc.iut.ac.ir

Y.A. KARAPETIAN, H.S. MKRTCHIAN & F. TATEVOSIAN.
Biology of PCN in Armenia.
Potato has a considerable gravity in agricultural industry of the Republic of Armenia. One of the most valuable resources to raise the gross output of this product is to fight the manifold pests and diseases including Globodera rostochiensis which causes the 30-50% losses in Armenia, sometimes rising to 70-80% in highly infected areas. To organize scientifically based actions, we have studied several biological and ecological aspects under specific soil and climatic conditions of Armenia. Globodera rostochiensis has been found in Armenia quite recently. It has a wide range of distribution and occurs at a number of basic potato areas. The most infected areas include Kamo, Martuni, Krasnoselsk, Aparan, Aragats. The tests concerned were carried out in Kamo area. With the population density of larvae and eggs being 2300 to 19200 per 100 cm³ of soil, the productivity was estimated to reduce from 7,0 to 83%. Beyond the general productivity reduction, the harm from potato nematode results in a sharp decline (down to 44%) of tuber commodity production. Threshold numbers to indicate infection in soil were proved to be 64 eggs and juveniles per 1 g of soil. It was confirmed by experiment that besides potatoes, Globodera rostochiensis affects tomatoes and eggplants, of weeds - black nightshade and henbane. Tests showed that potato nematode in Armenia produces mostly one generation. Juveniles of the second generation invade deep roots but do not manage to complete their development. It takes them 60 days to reach the brown cyst from the moment of root penetration. Dates for occurrence of adult males on the soil surface agree with those of white females. Living period of males is about 14 weeks.
Institute of Zoology, Academy of Sciences, P. Sevaka 7, Erevan, 375014, Armenia,tel.: (3742) 28-15-10; fax: (3742) 15-14-13, E-mail: LBALIAN@aua.am

V.S. LUTSAI & N.V. NAZAROVA.
Occurrence of Globodera rostochiensis in Pskov region of Russia.
The first outbreak of Globodera rostochiensis in Pskov region of Russia was recorded at 1963. At present time, this pathogen is present in 21 district on some 1073 ha, including 4,000 fields of private use. In private fields G. rostochiensis caused losses of potato yield estimated from 20 to 80% depending on susceptibility of cultivar, nematode density in soil and environmental conditions. Sites of infection were easier detected on sandy soils than on clay or moss soils. Nematode resistant cultivars Zhukovski Rannii, Prigozhii 2, Pushkinets and Sante were recommended for growing on infected with G. rostochiensis soils.
State Quarantine Inspection on Pskov region, Pskov, 180640, Russian Federation.

E.M. MATVEEVA & E.P. IESHKO.
Study of host-parasite interactions (potato and plant parasitic nematode Globodera rostochiensis Woll.).
An attempt to study (in vitro) the pattern of host-parasite interactions and to identify the factors controlling parasite abundance was made. Individual host response to nematode invasion and the status of new nematode generation were investigated. Ununiformity of nematode abundance in infested plants was revealed. The plant group exhibiting resistance to infection with the nematode was observed under low infection level. The increase of initial nematode numbers results in the decrease of plant resistance to the parasite which is expressed in similar infection intensities of individual hosts. The survival and reproduction capacities of nematodes were maximum under low infection level. High variance of the nematode reproduction coefficient (k) indicates considerable differences of k values that can be explained by individual features and protection properties of the plants. Increase of the infection level changes the variation range of plant infection intensity, reproduction coefficient considerably declines, the variance decreases. This indicates the more uniform distribution of parasites on plants. It was also established that the nematode morphology and fecundity permit to characterize the host-parasite interactions. The increase of the initial infection level causes the lowering of female size and the total number of eggs and larvae in newly-formed cysts. Thus, the intrapopulation regulators of nematode abundance leading to the decrease in the parasite survival, reproduction coefficient and fecundity under its high density start functioning.
Institute of Biology, Karelian Research Centre, Russian Academy of Sciences, Pushkinskaya str. 11, Petrozavodsk, 185610, Karelia, Russia. Tel.: (8142) 77 36 22, fax: (8142) 77 98 10. E-mail: matveeva@post.krc.karelia.ru

E.M. MATVEEVA, L.I. GRUZDEVA & L.P. YEVSTRATOVA.
Study of the interspecies relations between pathogens (golden potato nematode Globodera rostochiensis and fungus rhizoctonia) from potato varieties with different resistance to nematodes.
Two potato varieties grown in Karelia: Prigozhy-2 (resistant to the nematode), Detskoselsky (susceptible to the nematode) and the variety VIR-3 recommended for the growing from seeds. The latter has endotrophic mycorhiza but its resistance to the Globodera is not known. Host response to the infection by the nematode and fungus, rhizoctoniose development on plant organs and the status of new nematode generation were investigated. According to the results obtained, the variety VIR-3 can be considered susceptible to the globodera: the number of females developed on the plant roots increased 6 fold. When the plants were infected by two pathogens the final nematode abundance was twice lower than in the experiment with the nematode infection only irrespective of the potato variety. The of optimum conditions for the obligatory parasite development (globodera) were disturbed by the presence of the fungus, especially at the early potato growth stages which resulted in a considerable reduction of the nematode abundance and fecundity. Both pathogenes mutually affected each other. The presence of the nematode intensified rhizoctoniose development on the underground part of the plants (to 3.0 grade of the 4-grade scale, data on VIR-3). The association of the nematode and fungus caused a stronger pathogenic effect on the host-plant. It was expressed as a decrease in the growth intensity of the plants. Plants of the susceptible varieties VIR-3 and Detskoselsky showed the oppression of growth processes throughout the growing period and thoses of v. Prigozhy-2 - only in the first half of the growing period. Later on the inhibiting effect of the fungus ceased, the damaged tissues regenerated and the growth rate of the resistant plants increased.
Institute of Biology, Karelian Research Centre, Russian Academy of Sciences, Pushkinskaya str. 11, Petrozavodsk, 185610, Karelia, Russia. Tel.: (8142) 77 36 22, fax (8142) 77 98 10. E-mail:matveeva@post.krc.karelia.ru

L.A. PILIPENKO & D.D. SIGAREVA.
The mechanisms of interrelations in a system “Globodera rostochiensis - the potato host plant”.
In research of the function of the system of Globodera rostochiensis resistant plants, we observed the development of G. rostochiensis (Ro. 1) in vegetal experiments. For a period of two months, we determined the quality (the presence of larvae stages) and quantity (the ratio of stages, the duration of periods of development of the juvenile stages) of parameters of growth of nematodes on wild and cultured species as well as hybrids. Comparative analysis of the rate and peculiarities of onthogenesis changes in G. rostochensis (Ro. 1) during parasitism on specific plant groups, allowed us to assert the following types of resistance to G. rostochiensis: 1) antixenosis - larvae refuse to intake flood; hatched larva could not penetrate the plants; lost the ability to invade and died in the soil. (wild species S. chacoense (УК 21-2), S. chacoense (УК 21-33), cultured species S. rybinii (УК 259-32); 2) supersensitivity - invading juveniles of potato nematode penetrates the roots but die as a result of both local necrosis of root cells as well as of the deterioration of the whole organ (cultured species S. rybinii (УК 259-75); 3) antibiosis - in this case, we observed a disturbance of the normal biological cycle of the nematodes; halting of the development of mature female specimens and as the result - absence of females in the next generation (hybrids П 92.45-11, 92.302/40, ? 92.56/2, ? 92.78-13, ? 92.43-18, ? 93.69/2). The resulting resistant potato specimens can be considered to be the origins of nematode resistance and be incorporated into the selection process with given consideration to the type of resistance. The comparison of our results with those in literature allows us to confirm that the selection of nematode resistant potato species having different mechanism of immunity insures polygenetic control of indicators of resistance, which in this case tend to be more stable.
Institute of Plant Protection, Ukrainian Academy of Agrarian Sciences, Vasilcovskaya st. 33, Kiev, 252022, Ukraine, tel.: (044) 2631124, fax.: (044) 2632185, E-mail: nikol@mail.kar.net

D.D. SIGAREVA, L.A. PILIPENKO & E.B. SOSENKO.
The problem of cyst nematodes in Ukraine.
In the Ukraine, a significant part of the annual collective farms' crop yield is lost due to the poor control of the seed materials, characterized by the decrease in the quality of agricultural technology as well as insufficient application of pesticides. In the past several years, such conditions manifested in a sharp increase in zones of proliferation of the cyst nematodes of the potato and sugar beet plants and the destruction of 30 to 90% of the crop yield. Based on the analysis of the annual fluctuations in the numbers of cyst nematodes, we established that the key factors in the proliferation of the parasitic nematodes are biological, specifically the presence of the host plant and the density of the cyst nematode population in a field. Taken separately, the moisture and temperature levels during the period of growth and development of the plants have little significance - although we observed some tendency of better development in the pathogens at optimum to excessive moisture levels. We established that only one generation of Globodera rostochiensis develops on the potato while two generations of Heterodera schachtii develop on the sugar beet, perhaps with one more generation developing in the soil after the harvest of the crop. Along with improving chemical and agrotechonological methods, development of new nematode resistant breeds is crucial in the fight with cyst nematodes. The positive effects of cleaning the soil by planting nematode resistant plants, were observed in both resistant and antagonist breeds.
Institute of Plant Protection, Ukrainian Academy of Agrarian Sciences, Vasilcovskaya st. 33, Kiev, 252022, Ukraine, tel.: (044) 2631124, fax: (044) 2632185, E-mail: nikol@mail.kar.net

S.A. SUBBOTIN¹, P.D. HALFORD², A.D. WARRY² & R.N. PERRY².
Characterisation of populations of potato cyst nematodes from Russia using protein electrophoresis, RFLPs and sequences of rDNA and RAPDs.
Several populations of potato cyst nematodes from Russia were compared with populations from England, the Ukraine, Germany and The Netherlands using protein electrophoresis, sequences and RFLPs of ribosomal DNA and RAPD techniques. All populations from Russia were identified as Globodera rostochiensis. RAPD analysis revealed substantial genomic diversity among populations from Russia. Sequence analysis and RFLPs of ITS-PCR products showed that several haplotypes were present in the genomes of G. rostochiensis and G. pallida. Restriction patterns of PCR products for eight enzymes and restriction endonuclease cleavage maps for differentiation of these two species will be presented. Sequence dissimilarities between some haplotypes of G. pallida or G. rostochiensis were more than between the sequences of the three subspecies of G. tabacum.¹Institute of Parasitology of the Russian Academy of Sciences, Leninskii Prospect, 33, Moscow, 117071, Russia;²Entomology and Nematology Department, IACR-Rothamsted, Harpenden, Hertfordshire, AL5 2JQ, UK.

A.S. VASYUTIN & A.N. TRYAKHOV.
Golden nematode of potato distribution in Russia.
For the first time G.rostochiensis was detected in Kaliningradskaya region in 1949, which was the only infested region until 1961, and the total infested territory was 491 ha. In 1982 G.rostochiensis foci have already been registered in 29 regions on the territory of 11639 ha. State on January 1 of 1999 shows that G.rostochiensis was detected in 51 regions and the infested territory reached 41951 ha. During the period of 38 years it increased 85 times. In 1998 distribution of the golden nematode of potato in Kaliningradskaya, Novgorodskaya regions and Republic of Karelia made up correspondingly 18%, 14% and 9% of the territory under potato. In Leningradskaya, Kurskaya, Kalujskaya, Orlovskaya, Moskovskaya, Smolenskaya, Tverskaya and Sakhalinskaya regions percentage of infestation varied from 4 to 5 %. In the rest of the 40 regions distribution of G.rostochiensis made up 3 %. G.rostochiensis was not found on potato plots in Murmanskaya, Astrakhanskaya, Volgogradskaya, Samarskaya, Saratovskaya, Rostovskaya, Orenburgskaya, Omskaya, Tomskaya, Magadanskaya regions, in the Republics of Kalmykia, Adygeya, Altai, Dagestan, Ingushetia, Kabardino-Balkaria, Severnaya Osetia - Alania, Buryatia, Hakassia, Sakha (Yakutia), in Krasnodarski, Stavropolski and Krasnoyarski krais. The average distribution of G.rostochiensis in Russia makes up 1,28 % of the total territory under potato.
State Plant Quarantine Inspection of the Russian Federation 3, Orlikov pereulok, Moscow 107139, Russian Federation.

E.N. ZAKABUNINA.
The PCN Clobodera rostochiensis.
Clobodera rostochiensis is the object of internal and external quarantine in Russia. It is especially harmful in the private gardens and fields where potatoes are planted every year or in 2-3 years at the same place. The area invaded by PCN is still increasing. It is discovered in 9 districts of the Belgorod region on the 414 ha (1997). The infected plants produce a few weak stems which become yellow soon. In case of strong invasion the plant produces a bunch of the small roots which caused the significant crop losses. The following potato varieties have been tested in comparison with the common variety - Sineglazka: Redstar, Ukima, Berber, Asterics, Symphonia, Latona, Lookjanovskij, Rossiyanka. PCN cysts density in soil decreased by 55% under Berber, Rossiyanka, Symphonia, Asterics and Redstar and by 60 % under Ukima, Latona and Lukjanovskij, increasing by 110% under Sineglaska (control). Laton showed the 3 fold fertily comparing to the control.
Agronomy Dept., Russian State Agricultural Correspondence University, Fuchika 1, Balashikha, Moscow reg., tel.: 521-24-56, fax: 521-24-56, E-mail: Mezantrop@yahoo.com

Pinewood Nematode Bursaphelenchus xylophilus

K. FUTAI.
The mechanisms of the pine wilt disease.
Among various nematode caused plant diseases, the pine wilt disease seems to be an exceptional one, because huge pine trees are killed so promptly after the infection of a species of Bursaphelenchus nematode. We have not yet revealed all of the mechanism of the disease, though have many reports been published on this issue. The process of the pine wilt may be divided into two sequential but clearly separable steps, the initial events in disease development at tissue level, and the resulting events leading to final death at tree level. The most of the mechanism of the latter step have been revealed so far, but the mechanisms of the former step and causal relationships between these two steps have not yet been clarified.
Graduate School of Agriculture, Kyoto University, Kitashirakawa Oiwake cho, Sakyo-ku, Kyoto 606- 8502, Japan, Tel. +81-75-753-6060, fax +81 75-753-6173, email futai@kais.kyoto-u.ac.jp

N. KANZAKI, H. IWAHORI, K. TSUDA & K. FUTAI.
Comparison of characteristics among nine isolates of pinewood nematode from Japan.
Pinewood nematode, Bursaphelenchus xylophilus, the causal agent of pine wilt disease, invaded Japan perhaps from USA about one century ago. To examine the situation of species differentiation of the nematode, nine isolates of the nematode sampled at nine localities in Japan were compared in their characteristics such as DNA sequences of ITS 2 and HSP 70A regions, morphological characteristics (values "L", "a" and "V"), embryonic developmental velocity, and their pathogenicity to Japanese black pine seedlings at various temperatures were compared. DNA sequences were investigated as an index of nucleotide substitutions, and the other three polygenic characters were indices for genetic drift. The DNA sequences of ITS 2 and HSP 70A of the nine isolates examined were identical among the isolates and very close to those of US isolate "MO" from Missouri. This means that pinewood nematode are genetically homogeneous in Japan, though are many regional isolates in US with certain extent of nucleotide substitutions at ITS and HSP regions. So Japanese isolate of B. xylophilus seems to be derived from a limited number of populations probably origined in US, and have not yet produced nucleotide substitutions. While in the other three quantitative characteristics, however, are polygenic characters, and include many differences among nine isolates examined. This suggests that random genetic drifts are occurring in Japanese pinewood nematode populations. This drift may trigger farther differentiation among those populations.
Lab. of Environmental Mycoscience, Graduate School of Agriculture, Kyoto University, 606-8502, Kyoto, Japan, tel.: +81-75-753-6060, fax: +81-75-753-6173, E-mail: kanzaki@kais.kyoto-u.ac.jp, futai@kais.kyoto-u.ac.jp

O.A. KULINICH¹ & P.D. ORLINSKII².
Distribution and pathogenicity of pinewood nematode Bursaphelenchus spp. in Russia.
A survey of coniferous forest for nematodes in the genus Bursaphelenchus was made in several regions of Russia. The pinewood nematode B. xylophilus was not detected, however, the closely-related nematode B. mucronatus was found to be widespread, occurring in all of the regions which were surveyed. According to studies of Eroshenko and Kruglik (1996), B. mucronatus isolates from the Russian Far East are extremely pathogenic to different pine species grown under field conditions in Primorski Krai (Russian Far East). A field experiment to determine the pathogenicity of the different isolates of Bursaphelenchus mucronatus was conducted in the Moscow region of Russia. Two-year old, Scots pine, Pinus sylvestris, seedlings were inoculated with each of three B. mucronatus isolates: BmKOMY (from Komy Republic, Russia), BmRFE (from the Russian Far East, Primorski Krai) and BmCh (from China). The nematodes were extracted 2 months after seedling inoculation and again 1 year post-inoculation. Seedling stems, roots and soil were assayed for presence of B. mucronatus nematodes. No nematodes were found in seedling roots or soil. No seedlings had died 14 months after inoculation and only BmRFE isolate nematodes were extracted from seedling stem samples. All other nematode isolates failed to survive in seedlings.¹All-Russian Research Institute of Plant Quarantine, Pogranichnaj 32, Moscow region 140150, Russia, fax: +7 096 46 22628 E-mail: kulinich@garnet.ru;²State Plant Quarantine Inspection of the Russia Federation, Orlikov per., 1/11. Moscow 107139, Russia, fax: +7-095-9753971.

Stem Nematodes of the Genus Ditylenchus and Other Anguinidae

N.L. SEMIANNIKOVA & O.V. KOTSUBA.
Some aspects of the ecology of stem-nematodes of the genus Ditylenchus.
Natural areas of the most dangerous nematodes diseases of plants are formed owing to the existence of some wild plants which are infested by the plant - parasitic nematodes. The natural loci of the parasite-caused diseases of plants are potentially dangerous, they may cause the diseases in agricultural crops. Very often human activity results in shifting some natural area into agrocoenosis. It causes an increase in number of the areas of secondary origin and expansion of the area which they occupy; thus, the natural area turns into the source of epiphytic process. Biocenotic connections of plant nematodes with some plant species as well as the ability of plant-parasitic nematodes to stay in the mesabiotic condition in dried remains of plants and in soil for a long time promote the pest preservation. It has been established experimentally, that the Ditylenchus species are adapted to the mesabiosis. Mesabiosis duration was 9-13 years (D. dipsaci), 10 years (D. falcariae), 16 years (D. cirsii). D.dipsaci maintain the invasion ability in mesabiosis for 9 years. Nematodes from the wild plants (D. falcariae, D.circii) caused the non-specific diseases of agricultural crops after 6 and 2 years, respectively; invasion index of the extensiveness and the development of the abnormalities and as well as degree of harmfulness to a number of agricultural crops were higher then those of specific diseases.
Department of the Natural Sciences (Preparatory Faculty) of Kharkiv State Polytechnical University, 5-a, Vesnina St., Kharkiv, Ukraine, tel.: 43-50-94, fax: (0572) 43-50-94, E-mail: ut5ta@fcf.kpi.kharkov.ua, fcf@.online.kharkiv.com

L.V. SHUBINA.
Morphometric variability of stem nematode (Ditylenchus dipsaci) populations.
A comparative morphometric study of 13 D. dipsaci populations from 6 species of wild and cultivated plants (onion, garlic, red clover, strawberry) from Russia, Kazachstan, Bulgaria, Greece and Hungary, was carried out. D. dipsaci populations from different plant-hosts had been shown to have significant differences by a number of features (body length, vulva position, “a”, “b” and “c” indices), while those from one host species but confined to different habitats retain morphometric peculiarities, being indicative of genetic determination of the features studied. It was ascertained that nematodes extracted from resistant cultivars were characterized by less body and organs size, digestive and reproductive systems, in particular, as compared with those from the susceptible cultivars. The data obtained suggest that to a considerable extent D. dipsaci populations polymorphism is stipulated both by pecularities in parasite-host interrelations and their genomes. Support: RFBR (99-04-48332).
Institute Parasitology RAS, Leninskii prospect, 33, Moscow, 117071, Russia, tel.: (095) 9523145.

A.M. SIDORENKO.
Methods of detecting Ditylenchus destructor Thorne in potato tubers.
One of the more effective and cheap methods of controlling Ditylechus destructor Thorne is sorting the tubers before storing them in autumn and spring. The quality of sorting depends on the methods which aren't always optimal. In spring 1997-1998, with the aim of evaluating the effectiveness of the sorting methods, we examined the seeds of potato. We utilized the method of visual examination which allowed us to detect stains and other defects (i.e. characteristics typical of third-fifth stages of disease) of potato. We also used the method of removal of skin tissue and its examination under the microscope which allowed us to diagnose earlier stages of the disease. By the visual examination we established that the early-ripening species of Povin and Svetanok-Kievsky is 1.0 and 1.3 % damaged respectively, average-ripening Slovyanka and Gorlitsa- 1.6 and 5.4%, late ripening Rakoors and Zarevo- 0.3 and 0.8 %. Additional analysis which included the tuber skins, allowed us to detect specimens with invisible form of infection. The percentage of such tubers in samples of Povin and Svetanok-Kievsky was 3.6 and 3.2% respectively, Slovyanka and Gorlitsa- 3.0 and 3.1%, Rakoors and Zarevo 1.5 and 1.1%. It is known that the infection level of the tubers of the potato should not exceed 2.0%. Thus, using the method of analyzing the tuber skins under the microscope is crucial in the spring sorting of potatoes.
Institute of Plant Protection, Ukrainian Academy of Agrarian Sciences, Vasilcovskaya st. 33, Kiev, 252022, Ukraine, tel.: (044) 2631124, fax: (044) 2632185, E-mail: nikol@mail.kar.net

L.V. DOROFEEVA¹, P.A. SHRAMKO², S.A. SUBBOTIN³ & L.I. EVTUSHENKO¹.
New genera of bacteria the family Microbacteriaceae from galls induced by nematodes of the Anguininae subfamily.
The bacteria containing diaminobutyric acid in peptidiglycan from galls induced by Subanguina radicicola, Heteroanguina graminophila, Anguina agrostis, Anguina agropyri, Mesoanguina picridis on Poa annua, Calamagrostis sp., Festuca sp., Elytrigia repens, and Cousinia sp., respectively, have been attributed to 3 new genera of the family Microbacteriaceae: Agrevia gen. nov., Anguinobacter gen. nov., and Leifsonia gen. nov. The organisms of the new genera differ by morphology, peptidoglycan amino acids, composition of menaquinones, polyamines, polysaccharides, and physiological features and belong to different phylogenetic clusters determined by the analysis of nucleotide sequences of the 16S r-RNA gene. An accordance between the generic affiliation of bacteria and host nematodes has been revealed.¹Skryabin Institute of Biochemistry and Physiology of Microorganisms, Russian Academy of Sciences, Pushchino, Moscow Region, 142292, Russia, tel.: (095) 9257448, fax: (095) 9233602, E-mail: dorof@)ibpm. serpukhov.su;²Pushchino State University, Pushchino, Moscow Region, 142292, Russia, tel.: (095) 9238003, E-mail: pshramko@hotmail.com; ³Institute of Parasitology, Russian Academy of Sciences, Leninskii prosp., 33, Moscow, 117071, Russia, tel.: (095) 2367162.

E.Yu. GAVRISH¹, L.V. DOROFEEVA² , L.I. EVTUSHENKO², & S.A. SUBBOTIN³.
Ornithine-containing bacteria of the family Microbacteriaceae from galls induced by nematodes of the subfamily Anguininae.
The bacteria of the family Microbacteriaceae containing omithine in the cell wall were found previously in the phyllosphere of many plants. We have isolated quite a number of strains of this group from surface-sterilized galls induced by nematodes of the subfamily Anguininae. Most isolates with omithine in the cell wall, which predominant in a number of samples, are identified as members of the genera Curtobacterium and Microbacterium. Bacteria different from the known species of the genus Microbacterium have been found among the microorganisms from galls induced by Anguina agrostis and A. agropyri on Festuca sp. and Elytrigia repens. From galls on Festuca sp. induced by A. agrostis and A. graminis, novel bacteria distinguished remarkably from the validly described taxa on the generic level (by peptidoglycan structure, diagnostic sugars, and fatty acid composition) have been isolated.¹Pushchino State University, Pushchino, Moscow Region, 142292, Russia, tel.: (095) 9238003, E-mail: gkatya@mail.ru;²Skryabin Institute of Biochemistry and Physiology of Microorganisms, Russian Academy of Sciences, Pushchino, Moscow Region, 142292, Russia, tel.: (095) 9257448, fax: (095) 9233602, E-mail: evtushenko@ibpm.serpukhov.su;³Institute of Parasitology, Russian Academy of Sciences, Leninskii pr., 33, Moscow, 117071, Russia, tel.: (095) 2367162.

P.A. SHRAMKO¹, S.G. BEZBORODNIKOV², L.V. DOROFEEVA² & L.I. EVTUSHENKO².
Heterogeneity of restriction profiles of amplified ribosomal DNA of Rathayibacter spp. and related bacteria.
The bacteria from galls on wilding grasses (cereals) induced by nematodes of the subfamily Anguinae, close by the main generic criteria to Rathayibacter rathayi (formerly, Clavibacter rathayi) have been studied. The restriction analysis of amplified 16S r-RNA genes using restriction endonucleases Hae III, Hha I, and Mspl showed the presence of two groups, significantly differing in restriction fragments. The first group includes type strains of R. rathayi, R. iranicus, R. toxicus, and an isolate from the galls Anguina graminis on the leaves of Festuca sp. attributed to the new species R. festuci. The second group, comprising the bacteria from the galls of Anguina agropyri (Moscow Region), Anguina agrostis (Sakhalin), and Mesoanguina picridis (Turkmenistan), significantly differed in the profiles of restriction fragments from both Rathayibacter spp. and other validly described genera and species of the family Microbacteriaceae. The phylogenetic isolation ofrathayibacter-like isolates from the known genera, on the one hand, and the degree of heterogeneity by restriction profiles and phenotypical characteristics, on the other hand, allow them to be attributed to 3 species of the new genus.¹Pushchino State University, Pushchino, Moscow Region, 142292, Russia, tel.: (095) 9238003, E-mail: pshramko@hotmail.com;²Skryabin Institute of Biochemistry and Physiology of Microorganisms, Russian Academy of Sciences, Pushchino, Moscow Region, 142292, Russia, tel.: (095)9257448, fax: (095) 9233602, E-mail: evtushenko@ibpm.serpukhov.su

Virus Vectors

K. BOUTSIKA¹, K.R. WENDT², V.C. BLOK¹, S.A. MACFARLANE¹ & D.J.F. BROWN¹.
Molecular detection of trichodorid nematodes and tobacco rattle tobravirus.
Tobacco rattle tobravirus (TRV) transmitted by Paratrichodorus and Trichodorus species occurs as several serologically distinguishable strains that cause economically important diseases in flower bulb, vegetable, and potato crops, particularly in Europe and North America. A PCR assay with four rDNA primers derived from the 18S, 26S and 5.8S sequences has been developed which reliably distinguishes individual Paratrichodorus anemones, P. pachydermus, Trichodorus primitivus and T. similis nematodes from each other. The entire ITS region of rDNA of P. pachydermus was amplified by PCR, using 18s and 26s primers obtained from Xiphinema bricolensis. A further two primers, positioned in the 5.8S gene were designed and also have been used to provide a successful discrimination between the species. The amplified products were cloned and sequenced to obtain specific primers for each species. A RT-PCR assay established to detect TRV was further developed and reliably detects TRV present in single vector trichodorid nematodes. The highly sensitive RT-PCR technique detected TRV in mixtures of trichodorids in which only 1:100 nematodes were carrying virus. Also, this technique detects several different strains of TRV. Using these two assays it was possible to detect and distinguish strains of TRV and different vector trichodorid species occurring in a single individual bulk sample of nematodes extracted directly from field soil.¹Scottish Crop Research Institute, Invergowrie, Dundee, DD2 5DA, Scotland, U.K;²Ambion, Inc., 2130 Woodward Street, Austin, TX 78744-1832, USA.

A.S. EROSHENKO & L.P. ESIPENKO.
Longidords (Nematoda: Longidoridae) of the south of the Russian Far East.
Five species of virus-vector nematodes are known from the Russian Far East. Longidorus elongatus, L. martini and Xiphinema index are found in rhizosphere of arboreous plants in natural biotopes of Khabarovsky and Primorye regions. But they are not common species. Xiphinema radicicola is found on natural meadows of Khasansky district of Primorye regions. It is possible, there is north boundary of distribution of that subtropic species here. Xiphinema of. thornei (L=1.6-1.85 mm; с=57-65; с’= 0.8-1.0;V=77-56; stylet=130-148 (80-88+50-54)mm; leading ring 64-70 mm; spicules 46 mm) is widely distributed on the south of the Russian Far East. This species is found on Pinus, Ulmus,on Glycine max. This nematode is one of the serious root ectoparasites in pine trees nurseries in Amyrskaya and Primorye regions. (We recorded density of population ca. 120 specimens 100 cm³ ). Such number of specimens causes death of 1-2 years old seedling and great reduction of growing of 5-6 years old seedling of Pinus.
Institute of Biology & Soil Science, Russian Academy of Sciences, Far East Branch, 159 Stoletiya str., Vladivostok 690022 Russia, tel.: (4232) 311385, 310410, fax: (4232)310193, E-mail: zoology@ibss.marine.su

E. KARANASTASI, I.M. ROBERTS, S.A. MACFARLANE, & D.J.F. BROWN.
The location of specifically retained tobacco rattle virus particles in the oesophageal tract of the vector Paratrichodorus anemones.
Several Paratrichodorus and Trichodorus nematode species are specific vectors of serologically distinguishable strains of tobraviruses. ‘Tobravirus-like’ particles attached to the cuticle lining the pharyngostome and pharynx in both Paratrichodorus pachydermus and Trichodorus similis have been observed by electron microscopy of serial ultrathin sections cut from the nematodes and stained with osmium tetroxide. In a new study examination of P. anemones specimens revealed the presence of TRV-like particles binding specifically only to the cuticular lining of the lumen of the pharyngeal bulb in this species. Identification of the ‘TRV-like’ particles observed in these three studies was based on the particle morphology being similar to that of tobraviruses. However, it was not possible to provide unequivocal evidence of the viral identity of the virus-like particles. Immunogold labelling was applied to sections from the P. anemones specimens using an antiserum which specifically reacts with the coat protein of the virus. Aggregation of colloidal gold particles in the area where the ‘TRV-like’ particles occurred provided evidence of the viral nature of the particles. This immunogold labelling technique was also used to confirm the specific site of retention of TRV-strain PaY4 in P. anemones as being the posterior part of the pharyngeal lumen. Virus particles were absent in the most posterior part of the lumen of the pharyngeal bulb thus indicating a difference between the anterior and posterior regions of the pharynx. This difference may be associated with the occurrence of enzymatic or chemical reactions of glandular secretions emanating from the posterior ventro-sublateral oesophageal glands.
Scottish Crop Research Institute, Invergowrie, Dundee DD2 5DA, Scotland U.K.

S. MOLINARI.
Variability of Xiphinema populations according to isozyme profiles.
A screening of about 200 populations of Xiphinema spp. coming from all over the world was carried out by using isoelectrofocusing profiles of superoxide dismutase (SOD) isozymes. An automated electrophoretical system, which permits preprogramming of the chosen separation method and works with precast 0.45 mm thick gels, whose separation zone is only 3.8 x 3.3 cm, allowed to obtain reproducible and accurate profiles. Specific SOD profiles of X. index, X. italiae, X. pachtaicum, X. duriense, X. madeirense, X. santos, X. diversicaudatum, X. taylori, X. simile, X. coxi, X. vuitennezi were well characterized. Six electrophoretical groups were detected with populations of X. americanum -group not morphologically identified at species level. Several undefined profiles are currently being associated with their morphometric species. Intra-specific polymorphism is generally low but it can be consistent in certain species. Very distant geographical origin of populations of the same species did not result in high variability of the species-specific SOD profile. For instance, X. index from Argentina, Italy, Portugal, Malta and Crete had the same profile. Slight difference was found in the profile of Chile populations, although such a profile was also observed with a particular Italian population. An analogous screening is being carried out by using esterase profiles.
Istituto di Nematologia Agraria Applicata ai Vegetali, Via Amendola 165/A, 70126 Bari, Italy. Tel. 0039-80-5484188, fax 0039-80-5484165, email nemasm04@area.ba.cnr.it

N.D. ROMANENKO¹, B. CHOLEVA² & M. LISKOVA³.
The study of variability of morphometric characteristics of Longidorus euonymus (Nematoda; Dorylaimida) on different species host-plants in different regions of East Europe.
Different populations of L. euonymus from Russia, Bulgaria and Slovakia were studies and the variability of morphological characters depending on natural and climatic zones, geographical regions, host plants, soil and phytocoenosis type, was determined. The following morphometric characters were most variable; body length, length tail, hyaline part of tail, body diameter at vulva and anus, b and c values, whereas a, c, V, odontostyle length, diameter of lip region, guiding ring were considered to be the less variable. The most stable morphometric characteristics were spear length, length of basal part of oesophagus, length of genital branches.¹ Institute of Parasitology of RAS, 117071, Moscow, Leninskii prospect, 33, Russia, tel. 095 9523145, E-mail: ran@edunet.ru;² Biological Faculty of Sofia University "Kliment Ohridskii", Sofia, 1000, Russian boul., 15, Bulgaria, tel.: 87-39-96.³ Parasitological Institute of the Slovak Academy of Sciences, Hlinkova,3, 040 01, Kos'ice, Slovak Republic, tel.: 42195 63-31-411, fax: 42195 63-31-414.

N.D. ROMANENKO¹, M.A. KELDISH², V.G. ZAEC³ & B.F. TARAVALLI³.
Study of nematode and virus associations on leguminous plants in phytocenoses of Moscow region.
The distribution of nematode and virus associations, including nepo- and tobra- viruses and their nematode - vectors was studied in different phytocenoses of Moscow and Moscow region on leguminous species host plants in period 1998-1999. In discovered loci of nepo- and tobravirus infections quantity and correlation of eco-trophical group nematodes were studied. Associations of viruses (including nepo- and tobra- viruses) were found on 41 species of Leguminosales. Nepoviruses (TobRSV, AMV, RRSV, TomRSV, TBRV, SLRSV) dominated on leguminous plants. Tobravirus - TRV was discovered on 3 leguminous species. Cucumber mosaic virus and bean yellow mosaic virus dominated among other viruses on leguminous plants in Moscow region. The nematode vectors - Longidorus elongatus and Trichodorus similis were found in rizosphere of 9 species of leguminous plants in different phytocenosis types. The quantity of nematode vectors varied from single specimen to several tens specimens in 100 ml of soil and from 1 to 33 % of general quantity of nematodes. The level of coincidence of loci of nepo- and tobra- viruses and their vectors in the ecosystem was 19,5%. In laboratory experiments the possibility of transmission of of TomRSV, RRSV TobRSV by nematode L. elongatus and TRV - T. similis was demonstrated in biological and serological tests.¹Institute of Parasitology RAS, Leninskii prospect, 33, 117071, Moscow, Russia, tel.: 095 9523145, E-mail: ran@edunet.ru;²Main Botanical Garden RAS, 127276, Moscow, Russia, tel.: 095 4821135;³Russian University of Peoples' Friendship, 117198, Moscow, Russia, tel.: 095 4347007.

N.D. ROMANENKO¹, V.G. ZAEC², B.F. TARAVALLI².
Studies of damage nematodes Longidorus elongatus and Trichodorus similis on barley test-plants ( Hordeum vulgaris).
The studies of damage and influence nematodes L.. elongatus and T. similis on seed-germination, vegetative and root productivities of barley test-plants were carried out in conditions of laboratory and vegetative experiments. Reliable reduction of germination, vegetative and root productivities observed in the quantity of both nematode vectors from 1 to 10 specimens in 100 ml of soil. The most substantial and reliable (P=0,05) nematode T. similis reduced germination of barley seeds. Besides, both species (L. elongatus and T. similis) reduced biomass of barley test-plants (1,8-3 times).¹Institute of Parasitology RAS, 117071, Moscow, Leninskii prospect, 33 , Russia, tel.: 095 9523145, E-mail: ran@edunet.ru;² Russian University Peoples' Friendship, 117198, Moscow, Russia, tel. 095 4347007.

N. VASSILAKOS, S.A. MACFARLANE, & D.J.F. BROWN.
Vector transmissibility of a tobravirus mutant lacking a non-structural vector transmission protein can be reinstated through complemetation with a homologous vector transmissible isolate.
Vector transmission of tobraviruses by nematodes belonging to the genera Trichodorus and Paratrichodorus is characterised by a high degree of specificity, determined by components of the smaller RNA-2 segment of the virus genome. Both the coat protein and the 2b non-structural protein present in the RNA-2 segment of tobacco rattle and pea early-browning viruses are essential for transmission of the viruses by vector nematodes. Transgenic plant constructs incorporating separately the genes encoding the 2b transmission proteins of PEBV strain TpA56 and of TRV strain PaY4 were used in investigations to determine the role of this protein in the transmission process. To determine if complementation occurred between the plant expressed 2b proteins and the virus mutants one line of each construct was inoculated with virus mutants lacking the equivalent 2b protein. Results from these experiments indicated that complementation did not occur. Trichodorid nematodes were given access to plants co-inoculated with a vector transmissible mutant and an analogous mutant lacking the 2b-transmission protein in a further series of experiments. Both mutants were successfully transmitted to healthy bait plants, providing evidence of virus complementation whereby a non-vector-transmissible virus when in the presence of a vector transmissible virus in a plant can have its vector transmissibility restored. This research confirms the specific role of the tobravirus 2b protein in vector transmissibility of the viruses. In separate experiments the function of the 2b protein is being further investigated to determine if it causes conformational changes to the virus or vector to facilitate transmission. Alternatively the 2b protein may act as a ‘bridge’ between the virus and the vector, or it may affect virus movement and localisation in the plant making the virus available during vector feeding, or it may facilitate virus establishment in the new host plant.
Scottish Crop Research Institute, Invergowrie, Dundee DD2 5DA, Scotland, U.K.

E.K. VELLIOS, S.A. MACFARLANE, & D.J.F. BROWN.
Localisation of pea early-browning virus particles in plant roots determines their availability to virus-vector trichodorid nematodes.
Pepper ringspot virus, a member of the tobravirus genus, following mechanical inoculation of leaves of Nicotiana clevelandii plants spreads throughout almost the entire plant. However, root epidermal cells do not become infected with the virus. In a new study, following the mechanical inoculation of leaves of Nicotiana benthamiana with pea early-browning virus (PEBV), another member of the tobravirus genus, particles were observed in all types of tissues, including root epidermal cells. Large numbers of virus particles were observed in developing xylem vessels, but few or no particles were present in fully differentiated xylem cells. High concentrations of virus particles were present in root tip meristem cells and in root epidermal cells located immediately behind the meristematic region. Also, large numbers of virus particles were observed in living border cells that form the outer surface of the root cap, and which are frequently sloughed-off during root elongation. Many plant viruses do not infect meristematic tissue, therefore this property may represent an evolutionary adaptation to ensure high concentrations of tobravirus particles available for acquisition at this the preferred feeding site of vector trichodorid nematodes. Aggregations of virus particles in plant cells, as either paracrystalline structures in which virus particles align both side to side and end to end, or long chains of particles aligned side to side only is a common feature of tobraviruses. Plants inoculated with a PEBV mutant in which the 2b non-structural protein was not expressed resulted in the formation of very long sheets of side to side aggregated particles. However, paracrystalline aggregations did not occur. The 2b protein is essential for vector transmission, therefore a function of this protein may be to cause aggregation of particles in the correct paracrystalline formation to facilitate their acquisition by vector trichodorids.
Scottish Crop Research Institute, Invergowrie, Dundee DD2 5DA, Scotland, U.K.

T.C. VRAIN¹, R.T. ROBBINS², J.M. HALBRENDT³, & D.J.F. BROWN⁴.
PCR-RFLP profiles distinguishing population clusters of Xiphinema americanum group nematodes.
Xiphinema americanum group nematodes, several of which are vectors of nepoviruses, are distinguished on relatively minor morphological and morphometric differences. Individual specimens, from populations obtained worldwide, were used for an PCR-RFLP analysis of their ITS region. Results from this analysis revealed that the populations formed several discrete clusters. Fourteen populations from eastern North America formed a single cluster considered to represent X. americanum sensu stricto. Thirteen other populations from North America, and a population from Argentina that originally had been identified as X. rivesi, formed a cluster identified as representing X. rivesi. Four populations from northwest North America formed a cluster representing X. bricolensis; four populations from Italy, Crete and northern Greece each identified as X. pachtaicum formed a cluster with a population of X. pachydermum from the type locality in Portugal. Five populations from Slovakia and Russia formed a cluster representing X. taylori, and a population of X. brevicolle from the type locality in Brazil clustered with a population of X. diffusum from South Africa. Six populations from Australia formed a cluster with a population form South Africa and several other population clusters were apparent. The results of the analysis provide support for the recent synonymisation of X. diffusum with X. brevicolle, but suggest that a similar synonymisation of X. talyori with X. brevicolle is probably incorrect. It appears that X. rivesi is widespread in North America whereas X. americanum sensu stricto is apparently restricted in its distribution to eastern North America, as had been suggested previously.¹ Pacific Agri-Food Research Centre, Summerland, BC, V0H 1Z0, Canada;²Nematology Laboratory, University of Arkansas, Fayetteville, AR 72701, USA;³Fruit Research Laboratory, Pennsylvania State University, 309 University Drive, Biglerville, PA 17307, USA;⁴ Scottish Crop Research Institute, Invergowrie, Dundee DD2 5DA, Scotland, U.K.

Entomopathogenic Nematodes

P.N. AN.
The naturally determined distribution of Mermithides (Mermithidae; Nematoda) in different types of Kyrgyzstan water flows.
It was revealed, that Mermithides inhabits all types of streams and rivers, but number of species were different. The intensively inhabited small and medium size rivers, which falls into big rivers or lakes, have the number of 10 species: Gastromermis interstitialis, G. kolleonis, G. violettae, Hydromermis angusta, H. palustris, H. pratensis, H. sibirica, Isomermis rossica, Romanomermis rubzovi, Tetramermis acauda. There are widely inhabited spring streams. There are as following 7 species: Gastromermis iinterstitialis, G. kolleonis, G. violettae, Isomermis rossica, Romanomermis rubzovi, Tetramermis acauda, Gastromermis sp. 2. It's comparatively poor represented fauna of mountain Mermithides (2 species - Gastromermis violettae, Isomermis rossica) and big rivers (3 species - Gastromermis interstitialis, G. kolleonis, G. violettae). It was determined, that under the necessary conditions Mermithides inhabits water flows of all characteristics, from spring streams to big rivers, including high altitudes, at the level by 3.500 m above sea.
The Biological Institute of NAS, Bishkek, 720071. Kyrgyzstan. Tel. (996-312) 255370.

V.N. CHIZHOV¹, N.N. BUTORINA² & S.A. SUBBOTIN³.
Entomopathogenic nematodes of the order Tylenchida (Nemata): new formal classification.
New classification of entomopathogenic Tylenchida (EPT) based on the literature data and original results, is proposed. Phylogeny and the taxonomic composition of the main morpho-ecological groups of EPT: Spahaerularioidea, Allantonematoidea and Iotonchoidea is doscussed. Original diagrams of all known life cycles of EPT and their evolution is given. Four new subfamilies of EPT are proposed. Key to families and subfamilies of EPT is given.¹Mira pr. 184-1-53? Moscow, 129301;²Institute of Inner water Bodies RAS, Borok, Jarslavl reg., 152742;³Institute of Parasitology RAS, Leninsky pr. 33, Moscow.

H.V. DUBININA¹, HANS-PETER FAGERHOLM², A.N. ALEKSEEV¹ & L.N. ANISYUTKIN¹.
The first record of the Dipetalonema sp. mermithid larvae in Ixodes persulcatus (Acarina, Ixodidae). This is the first record of a mermithid (Nematoda, Mermithidae) parasite discovered in the body cavity of Ixodes persulcatus. Adults and nymphs of this tick species were collected at the St. Petersburg (Russia) vicinity during 1997-1999. Out of 1573 adults 4 nematods were parasitesed (females 0.4%, males 0.12%). One nymph out of 315 specimens collected during 3 y obtained a mermithid (0.32%). Only in one female 3 worms were discovered. Ticks were dissected and investigated under the microscope (40x10) in the darkfield for the spirochete determination: 250 fields of each slide. Occasionally met mermithid larvae were fixed in the formol, then mounted in the lactophenol and studied with a Nomarsky contrast microscope. The length of larvae was 210-250 mm, and maximum width 9-10 mm. The worm was not filiform, but had rather an even width. The head ends rather abruptly, while the tail get gradually narrower. The point of the tail is not very sharp, but rather somewhat rounded at the distal-most point. The measures and the form of the worm were very similar to a sausage or a thickening moulting forms microfilaria Dipetalonema rugosicauda, which is a common parasite of ticks Ixodes ricinus and a roe deer Capreolus capreolus (Winkhardt, 1980). There are two differences between D. rugosicauda and discovered by us Dipetalonema sp. Dipetalonema sp. had not a rounded front end but rather a square like one. Winkhardt (1980) got filariae infected specimens only from I. ricinus nymphs, which were attached to the roc deer ears, whereas we obtained Dipetalonema sp. specimen from one of the hungry nymphs collected from vegetation by flagging. It permitted to suggest that described by us mermithid was got firstly by the feeding larvae and then transferred to the nymph transstadially. In St. Petersburg vicinity roe deers are absent. These two last facts and the difference in the shape of the worm and their tick-host strongly suggest that we have discovered a new species of the genus Dipetalonema with an unknown life cycle. The rarity of filariae detection (0.4 % or less) may have a cause of the unspecific search method, which was used not for filariae but for borreliae determination. Support: the State Science and Technology Program "Biological Diversity-98-99", in part by Grant 9600864 of the Danish Research Councils, and in part by Grant N 98-04-49899 from the Russian Basic Research Foundation.¹Zoological Institute, Russian Academy of Sciences, 190034, St.-Petersburg; ²Institute of Parasitology, 20520 Abo, Turku, Finland.

G.B. Fedorova¹, T.P. Yudina², A.P. Zarubina² & G.S. Katrukha¹.
The study of the antibiotics from Photorhabdus luminescens, strain ZM1, the bacterial symbiont of Heterorhabditis sp.
The bacteria Photorhabdus luminescens, strain ZM1, isolated from the larvae of nematodes Heterorhabtidis sp. (Moldavia strain) were kept in the Laboratory with the use of specific selection methods.. This strain as well as the majority of genera Photorhabdus bacteria is characterized (when cultured in vitro) by the phase variability: the cells of the primary form produce antibiotics whereas the cells of the secondary form don’t do it. The majority of the cells of this strain belongs to the “intermediate” variant with low bioluminescence and with moderate antibiotic activity. We have demonstrated that in submerged culture the Photorhabdus bacteria produce the antibiotic complex with the broad spectrum of antimicrobial activity. Using organic solvent extraction followed by column and silicagel thin layer chromatography this complex was separated into individual compounds. Two major substances of this complex, the antibiotics A and C, were obtained in the chromatographycally pure state. The detailed study of the biological and physico-chemical parameters (mass-, NMR-, UV-, IR-spectroscopy) in combination with computer data base analysis (BNPD, J. Berdy, Hungary) allows to identify the antibiotic A as a new member of isocumarine family, and the antibiotic C as the new natural compound. The study of the structure and functions of antibiotics A and C is now under progress.¹Institute of New Antibiotics RAMS, B. Pirogovskaya, 11, Moscow, Russia, tel.: (095) 246-6983, fax: (095) 245-0295, E-mail: instna@online.ru;²Dept. of Microbiology, Biol. Faculty, Moscow State University, Moscow, 119899, Russia, tel.: (095) 939-5603.

R. GAUGLER¹, G. GREWAL², H. KAYA³, D. SMITH-FIOLA⁴.
Quality assessment of entomopathogenic nematodes.
The quality of the most widely commercialized entomopathogenic nematodes, Steinernema carpocapsae and Heterorhabditis bacteriophora, was assessed from thirty shipments from six U.S. suppliers mailed to three locations. These suppliers comprise a cottage industry primarily aimed at a mail order home & garden market. Most companies were accessible, reliably shipped pure populations of the correct species on time, in sturdy containers, often with superb accompanying instructions. Nematodes were received in satisfactory condition with acceptable levels of viability. Consistency, however, was a significant problem. Most shipments did not contain the expected nematode quantity, and one shipment had no nematodes. Pathogenicity of several products against Galleria mellonella larvae was not equivalent to our controls. Heterorhabditis bacteriophora was not always available when ordered. A few products contained mixed populations of both nematode species. Application rate recommendations provided by some suppliers were unsound. We conclude that the entomopathogenic nematode cottage industry generally lacks rigorous quality control, that self-regulation is impractical without feedback on quality, and that consumers are unable to provide this feedback. Extension will need to provide feedback that enables consumers to make informed decisions and encourages improved reliability by the industry.¹Department of Entomology, Rutgers University, New Brunswick, New Jersey 08901-8536, E-mail: gaugler@rci.rutgers.edu;²Department of Entomology, Ohio State University, OARDC, Wooster, Ohio 44691;³Department of Nematology, University of California, Davis, California 95616;⁴Rutgers Cooperative Extension, 1623 Whitesville Rd, Toms River, New Jersey 08755 USA.

A. HARMAN¹, J. WINTER² & D. HARMAN³.
Morphometric description of a bursate nematode inhabiting the larval cavities of the locust borer, Megacyllene robiniae (Forster).
From among a guild of nematodes associated with tunnels created by the locust borer larvae, the first to appear and be collected is a new species of the family Cylindrocorporidae Goodey, 1939 and the genus Cylindrocorpus Goodey, 1963, (syn: Myctolaimellus Andrassy, 1984). Although it shares the defining feature of this family, a cylindrically shaped fused precorpus and corpus, this small nematode differs from other species in the genus by the shape and characteristics of the bursate tail as well as other basic morphometrical distinctions. The females of this species on average are larger than the males and their characteristics include an amphidelphic reproductive tract with long, crossing ovaries, an equatorial vulva, and a tapered tail. The characteristics of the male include a bursate, peloderan tail, a single testis, slightly reflexed anteriorly, and paired, knobbed spicules. A distinctive gubernaculum is also present.¹Frostburg State University, 101 Braddock Road, Frostburg, MD 21532, United States tel: (301)-687-4175; E-mail: AHarman@mail.Frostburg.edu;²Frostburg State University, 101 Braddock Road, Frostburg, MD 21532, United States, tel: (301)-689-2892, E-mail: Johnwinter50@hotmail.com;³Appalachian Laboratory, 301 Braddock Road, Frostburg, MD 21532, United States, tel: (301)-689-7164, E-mail: Harman@al.umces.edu

T. KURBANOVA & I. AKOPOVA.
To the study of spontaneous helminthoinfection of Polyphaga aegyptiaca (Blattoptera, Polyphagidae).
Data of the infection Polyphaga aegyptiaca L. with spirurides Streptopharagus kutassi Schultz and larvae Physaloptera sp. 2 Muschkambarova and Physaloptera sp. 3 Muschkambarova (Spirurida, Physalopteridae), intestlnal endoparasites Galebia aegyptiaca G. (Oxyurida, Thelastomatidae) in Turkmenistan are given. In Central Kara-Kum nematodes of suborder Spirurata in the Egyptian cockroaches were not revealed. For the first time entomopathogenic nematodes Steinernema glasseri Steiner, 1929 (Rhabditida, Steinematidae) were revealed in Blattoptera. Mixed infection with larvae of biohelminthodes and entomonematodes is noticed in S. kutassi and Physaloptera sp. 2. For the first time P. asgyptiaca is considered to be as the definite host for S. galssseri and as the intermediate host for the larvae of Physaloptera sp. 2 and Physaloptera sp. 3. Species S. glasseri and G. aegyptiaca are found in Turkmenistan for the first tirne.
Institute of Desert of plants and animals world, Ministry of Nature Use and Environment Protection of Turkmenistan, 6, Azady, Ashgabat. 744000, Turkmenistan, tel.: (363) 390485, fax: (095) 119-0368.

K. TSUDA & K. FUTAI.
The biology and the morphological characteristics of Iotonchium species.
The tylenchid nematode Iotonchium ungulatum is the causal agent of the gill knot disease of the oyster mushroom, Pleurotus ostreatus, in Japan. During an investigation of host range of I. ungulatum, we discovered another undescribed species of Iotonchium (Iotonchium sp. 1) from fruit bodies of Cortinarius spp. in Kyoto. Either of these two Iotonchium species possesses four adult stages; mycetophagous female, infective stage female, male and entomophagous female. Among the Iotonchium species described so far, only one species, I. californicum, has been known to possess both of the mycetophagous and entomophagous stages. There are several prominent differences in the morphological characteristics both in the mycetophagous and the entomophagous females between these three species, though are their life cycles similar. Either of these three Iotonchium species has respective fungus and insect hosts. The mycetophagous females of I. ungulatum inhabit in the knots on the gills of the fruit bodies of P. ostreatus and P. pulmonarius. Those of Iotonchium sp. 1 inhabit in the stipes of the fruit bodies of C. subalboviolaceus and two unidentified Cortinarius spp. Those of I. californicum live in the fruit bodies of Agrocybe praecox. The entomophagous females of I. ungulatum, Iotonchium sp. 1 and I. californicum parasitize fungus gnats Rhymosia domestica, Exechia dorsalis and Mycetophila fungorum, respectively. The mycetophagous and the entomophagous stages of other Iotonchium species have not yet been reported, though have been found in various basidiomycetous fungus suggesting they also have both of the mycetophagous and entomophagous females.
Lab. of Environmental Mycoscience, Graduate School of Agriculture, Kyoto University, 606‑8502, Kyoto, Japan, tel : +81-75-753-6060, fax : +81-75-753-6173, e-mail : futai@kais. kyoto-u.ac.jp

J.M. WEBSTER, K. HU & E. HUI.
Host finding and infectiousness of entomopathogenic nematodes.
Infective juvenile (IJs) entomopathogenic nematodes exit the cadaver of their host insect admidst a population of their respective bacterial symbiont and the metabolic products resulting from parasitism of the insect. The emerged IJs are attracted and repelled by a multitude of chemical cues from the surrounding flora and fauna as they move vertically and horizontally through the soil. The speed and distance that the IJs move is affected by a range of biotic and abiotic factors. The antibiotics and nematicidal substances released from the cadaver into the soil in association with the IJs temporarily and locally diminish soil populations of bacteria and fungi and probably paralyze nematodes in the immediate vicinity. These temporary influxes of secondary metabolites could cause local, rapid changes in the rhizosphere microflora with subsequent feedback through chemical cues to the foraging IJs. In the regions of root growth to which root feeding insects and IJs are attracted the IJs forage for a host insect. The availability of host insects and the influence of organisms in the rhizosphere strongly influence the foraging behaviour and the number of IJs in the soil over time.
Centre of Environmental Biology, Simon Fraser University, Burnaby, Vancouver, B.C., V5A 1E6, Canada. tel: (604) 291-3336, fax: (604) 291-3496, E-mail: jwebster@sfu.ca

T.G. YUDINA & A.P. ZARUBINA.
Antibiotic activity and toxicity of protein inclusons from Photorhabdus luminescens symbiotic with entomogenous nematodes Heterorhabditis.
The protein inclusions were recovered from the Photorhabdus luminescens, strain ZM1. In obtained preparation for dissolving only the polyedric shape structures (usually with four and six-sided) of different size were revealed using SCAN microscopy. The polypeptides obtained from these inclusions have the antibiotic activity against some micrococci, rodococci, also Bacillus subtilis, Nocardia calcarea, Streptomyces chrysomallus, E. coli, Pseudomonas aeruginosa, Zoogloea ramigera. The spectra and values of antibiotic activity of polypeptides from inclusions of Ph. luminescens were different from those obtained for inclusion proteins from Xenorhabdus and they were very different from those obtained for inclusion proteins of entomopathogenic bacilli. The primary control of toxicity of proteins obtained from inclusions of Ph. luminescens, B.thuringiensis, and also bacitracin was investigated using test-system “Ecolyum-05” (Moscow State University) on basis of recombinant photostrains E. coli with lux-regulon from the sea photobacterium or from Ph. luminescens ZM1. The bioluminescense of recombinant E. coli was inhibited by these polypeptides according to the following sequence: bacitracin > d-endotoxins > polypeptides Ph. luminescens. The difference in toxicity of these antibiotic compounds was demonstrated. Different mechanisms of action of investigated compounds on procaryote cells were suggested. The ecological role of antibiotic activity of different inclusion proteins was compared.
Dept. of Microbiology, Moscow State University, Vorobjevi Gory, 119899, GSP Moscow, Russia. Tel.: (095) 9394545.