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Many of the major development in the field of parasite community ecology have been due to a switch in focus from a search for pattern to investigation of the processes that produce those patterns. This switch has been accompanied by a recognition that different processes operate at the scale of the individual host (processes determining host specificity and attributes of the niches of the parasites), within the unit of habitat (processes determining population dynamics, exchange of parasites, and transmission), and among units of habitat (processes determining colonization, extinction, or local speciation of parasites). Further developments are likely to depend upon the coordinated use of modles, experimental approaches, and field ofservations aimed at clarifying the conditions under which the processes at each scale became patricularly important.

Larva and nymph of Dermacentor ushakovae Filippova et Panova, 1987 are described in a differential aspect in relation to all species of the subgenus Serdjukovia, a special attention being paid to differential diagnostics with the close species D. marginatus Sulz. and D. niveus Neum. The both phases are described with regard for variability of samplings from 5 sites of D. ushakovae distribution area: Zaisan hollow, valleys of the Chilik, Sumbar and Chandyr rivers (laboratory cultures from identified parents); Issyk-Kul hollow (collection in nature with partial bringing up to mature phase). Variability range of differential characters within the area is shown. The most stable species-specific characters of D. ushakovae are chaetotaxy of idiosome, proportions of gnathosome and its organs, peritrema.

The distribution of fleas of small mammals and birds in the nidi of tick-borne encephalitis was analysed. 23 species were recorded from the forest-park zone. Palaeopsylla soricis starki, Amalaraeus penicilliger penicilliger, Megabothris rectangulatus, Ctenophthalmus assimilis, Hystrichopsylla talpae were dominant. They amounted to 90% of the total number of fleas. The greatest species variety of fleas was noted in afforested low-lying parts with rich species composition of hosts.

The rate of irritability and "aggressiveness" (attacking activity) at the contact with DDT was determined for all main potential vectors of malaria in the USSR. Great species differences were found out. Changes in the irritability and "aggressiveness" rates with growth of resistence to DDT were traced. The knowledge of resistence rate, initial data on the irritability and "aggressiveness" of each species and the main trends in the changes in mosquitoes behaviour under the effect of DDT makes it possible to predict the effectiveness of DDT in concrete situations. The results of visual observations on the behaviour of malaria vectors in dwelling treated with malation and propocsur, subsititutes for DDT in control on resistant populations, are given.

The paper deals with the description of the species Simulium (Argentisimulium) beringovi sp. n. new to science as well as larvae and pupae of Ahaimophaga komandorensis Rubzov.

The use of Folgen-like electron microscopy reaction has revealed particles in the cytoplasm and nucleus of the dysentery amoeba trophozoites which in their size and resistance to acidic hydrolysis and in their affinity for uranilacetate are similar to tightly packed elements of the bacterial genome. On this basis a conclusion was drawn that some fragments of genomes of phagocitic bacteria can be preserved in the amoebal cell. The community of microorganisms consisting of trophozoites of the dysentery amoeba and bacteria of the intestinal flora is supposed to be a suitable model for studying the possibility of penetration of transgenetic elements from procaryote to eucaryote.

Experiments on cross infection of peritoneal macrophags of mice with Leishmania of reptiles L. gymnodactyli and free cells of abdominal cavity of caucasian Agatna (some part of which is composed by fibroblasts) with Leishmania of mammals L. major and L. donovani have shown the possibility of reproduction of the above species both in reptiles and mammals. The persistence of L. gymnodactyli and L. major in macrophags of mice was traced up to 10 days, the abundance of L. gymnodactyli during the whole period of observations being lower than that of L. major. The abundance of the above Leishmania in these cells happened to be higher than in the cells of reptiles. In the cells of reptiles the infection with these three species of Leishmania was eliminated by 5—6 days. More activite internalization of Leishmania of reptiles into cells of reptiles as compared to Leishmania of mammals was revealed that, apparently, reflects a definite degree of their adaptation to existence in reptiles in vivo.

Spectrophluometric analysis has revealed substances with spectral characteristics identical to these of serotin and dophamine in tissue extracts of Polystoma integerrimum. A possible function of the substances is discussed.

A new cestode species, Diphyllobothrium klebanovskii sp. n., is described on the basis of experimental examination and morphological study of 51 specimens expelled from men in lower part of the Amur river and 18 specimens expelled from golden hamsters. The larval stage of this cestode is plerocercoid of type F, which is localized in muscles of Oncorhynchus keta and O. gorbuscha. D. klebanovskii sp. n. is a marine species, it differs from D. latum and other species of the genus Diphyllobothrium.

8 species of cestodes belonging to the family Hymenolepididae were recorded from Polysticta stelleri (Pall.) in the Chaun lowland. A new species of hymenolepidids, Microsomacanthus polystictae sp. n., differing from close (by the length of proboscis hooks) species of the genus in the structure and size of the copulatory organ is described. Brief diagnosis of the new species: cestodes small, specimens ending with hermaphrodite proglottids 2.44 to 2.91 mm long. Proboscis hooks 0.038 to 0.042 mm long, blade 0.011 to 0.012 mm long. Strobila of maximum length with 84 proglottids. In young male proglottids the aporal testis half as large as poral and median ones, in well-developed proglottids testes 0.020 to 0.026 X 0.023 to 0.032 mm. Bursa of cirrus 0.150 to 0.190 X 0.020 to 0.028 mm. Cirrus 0.107 mm long, basis 0.008 to 0.011 mm wide, median part 0.012 to 0.014 mm wide, apical part 0.004 mm wide. Cirrus armed with spines 0.003 to 0.004 mm long. Ovary bilobate, yolk gland compact. Spermatheca small, situated medially, in front of poral ovary lobe. Copulative part of vagina sacciform, 0.086 to 0.118 mm long, 0.023 to 0.037 mm maximum width. Distally and proximally vagina with muscular sphincters. Uterus sacciform, with 35 to 40 embryos. There were no mature "eggs" in the material.

It has been established that cysts S. fusiformis and S. gigantea of parasites isolated from oesophages of infected buffaloes and sheep have the identical set of free amino acids and their metabolites. These species differ from each other in 7 components of 34 studied that points to their metabolic closeness and to specific differences of sarcocysts from different hosts.

Hymenolepis macrorchida (Kotlan, 1921), a cestode of New Guinea parrots, possessing a small number (3 to 4) of testicles, belonging to the family Hymenolepididae to which it has been assigned for more than half of the century, is transferred to the family Davaineidae and designated as Idiogenoides macrorchida (Kotlan, 1921) comb. n.

Damage done to skin of cattle and defects of raw leather, which are caused by ixodid and demodecid ticks, parasitic on animals, are described. Losses of tanning industry amount to 1.6 to 3.7 thousand roubles per each thousand of finished box-calf leathers.

A description, figures and differential diagnosis of a new species of trematodes, Koellikeria inbumi sp. n., of the family Didymozoidae found in the abdominal cavity and under gill cover of Brama brama and Brama sp. in the Indian and Atlantic Oceans are given. The new species is close to the single member of the genus, K. okeni (Kolliker, 1849) Cobbold, 1860, but differs from it in the pressence of the "egg reservoir", biramous ovary, shape of the female posterior portion, considerably smaller sizes of the abdominal sucker, sizes of males which are 4 to 5 times smaller than these of K. okeni.

A description, figures and differential diagnosis of a new species of trematodes of the family Didymozoidae found in Scomber japonicus in the north-western part of the Pacific are given.

Summary is absent.