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Experiments on the artificial and natural feeding of infected Dermacentor marginatus Sulz. have revealed the salivary-oral mechanism of the transmission of the tularemia agent. 72 ticks were artificially fed (23 nymphs and 49 adults). 4 cultures of Francisella tularensis were obtained (1 from nymphs, 3 from adults) from capillaries where ticks injected the tularemia bacteria together with saliva. During the natural feeding on guinea pigs the causative agent of tularemia was found to be transmitted through the bite of adult infected D. marginatus, their excrements being isolated by placing the caudal part of the tick into the rubber sac. The salivary-oral mechanism of the transmission of tularemia infection by D. marginatus is regarded by the authors as a specific inoculative one.

Absorbtion of O₂ and excretion of CO₂ in unfed males and females of Hyalomma asiaticum were studied by means of differential Barkroft's microrespirometer. In individuals infected with Coxiella burneti the respiration rate was the same as in uninfected ones. In ticks infected with Dermacentroxenus sibiricus the rate of absorbtion was 25% and the rate of excretion 24% higher.

Experiments with larvae and nymphs of Haemaphysalis concinna from the Far East have demonstrated that photoperiodic reaction is involved into regulation of the seasonal development of the tick. Long-day conditions enable the non-diapause development of immature stages and the aggressiveness of hungry nymphs. Short-day conditions induce the diapause of engorged larvae and nymphs, as well as the inactivity of hungry nymphs. Seasonal adaptations in H. concinna and Ixodes ricinus are discussed.

In the article is presented the material on the distribution and the specific composition of hosts Ixodes pavlovskyi in north-eastern Altai.

The metamorphosis of fleas Xenopsylla skrjabini and X. nuttalli was observed experimentally at the temperatures from 8 to 35° within 35—100% of relative humidity. More effective development of all the preimaginal phases was at temperature 15—32° within 75—92% of relative humidity. The temperature 20—22° by relative humidity 75—80% for X. skrjabini and 85—90% for X. nuttalli should be considered the optimum of the development of all the phases. The lower limit of X. skrjabini and X. nuttalli development is near to 10° C, the upper one proved to be the temperature 34° C. X. skrjabini highly develop in the wider zone of a divergence from optimal conditions than X. nuttalli and X. gerbilli minax.

A suggested system of control measures against mosquitoes in foothill regions of Kazakhstan is directed primarily to the eradication of breeding places of these bloodsuckers. Chemical methods of control should be employed only in extraordinary cases.

In this article are given the results of some tests of N-benzoilderivatives, tetra- and deca-hydrohynoline and some of their homologues possessing an effective repellent capability. It is found that N-benzoilpiperidine and N-benzoil-2-methyl-5-ethylpiperidine have an acuter repellent action.

Carbophos (2.5%—60 l per hectar; 5% — 30 l per hectar) causes a full death of larvae and pupae of mosquitoes in the natural waterbodies, having an average depth of 35 cm. Carbophos in the indicated standards has a disastrous effect on the plankton. It is desirable to abstain from the spraying the waterbodies of economic importance.

Red salmon is one of the most suitable objects for working out the methods of differentiation of local stocks as far as it stays in fresh waters for a long time. On the basis of studies of parasite fauna of freshwater and anadromous fishes from Kamchatka some freshwater parasites were chosen as indicators because they accompany Oncorhynchus nerka during all migrations. For some parasites quantitative characteristics were used for the differentiation of local stocks. The key permits the differentiation of local stocks from Kamchatka only during the first months of their life in sea and during migration period of mature red salmon.

There was studied the influence of 12 species of trematodes larvae on the reproductive organs of 5 species of gastropods. The parasites locating in the organs of the reproductive system, cause a destruction of the connective tissue and also degenerate changes in the embryonic epithelium. Side by side with this the decrease of supplies of glycogene phospholypides and RNA is available both in the embryonic epithelium, in the oocytes and in the male gametes. By a high intensity of invasion a parasitic castration of hosts was observed.

The life cycle of Hyptiasmus oculeus (Cyclocoeliidae) is detected. The rates of the development of the stages are established. The influence of infestation rate on mollusks, growth, development and productivity of redia is elucidated.

On the basis of the comparative study of the morphology of Leucochloridium phragmitophyla from different hosts is distinguished a new form from Motacilla flava — L. phragmitophyla f. microbursata differing from the main one by small dimensions of bursa cirri.

In the result of the study of monogeneans Gonoplasius longirostri (Robinson, 1961) and G. truttae Dillon et Hargis, 1965, for the latter species is substantiated a new genus Kahawaia gen n. Its differences from the genus Gonoplasius consist in another character of hooks of genital atrium, in the absence of sclerotized cuticular cavities near vaginal zone, and also in the absence of stilett-like appendages on the dorsal part of the middle plate of opistohaptor. It is given a diagnosis of the genus Kahawaia and a new description of Kahawaia truttae (Dillon et Hargis, 1965) comb. n.

Cysticercoids of Hymenolepis nana were recorded for the first time in the mesenteries lymphatic nodules from white rats.

There has been studied the development of the camel's nematode Dipetalonema evansi in the intermediate hosts — mosquitoes Aedes caspius Pall. till invasional stage. A derailed description in the larvae within the days from 1 to 10 is presented.

It is little known about the structure of the subcrystalline layer of the cystforming nematodes of the genus Heterodera. By this layer the females' bodies of these worms keep off the unfavourable conditions of the environment. Heterodera ustinovi, sp. n. has a very original structure of the subcrystalline layer (fig. 1), which consists of the rather large polygonal areas and seems to be uniform. H. salixophila, sp. n. has these areas more smaller, sometimes irregular in form and stretched out along its length (fig. 2). It is possible to use the structure of the subcrystalline layer as a supplementary feature for the definition of the species of these worms. The first previously mentioned worm is a parasite of the roots of Agrostis vulgaris With., the second is the parasite of the roots of Salix purpurea L. and some other willows. Detailed descriptions of the worms are given.

The fauna of mixosporidians of the Kuban river is much poorer in species as those of other rivers entering the Black and Azov Seas. This is associated with the influence of salinization in the mouth of the river and strong current in the middle part. Especially poor are the species with spores slowly sinking down and easily drifted by the current. These species are mainly recorded from the mouth of the Kuban.

There has been described a new species of mixosporidia Fabespora nana gen. et sp. n. from the gall-bladder of the Black Sea fishes (Gobiidae and Scorpaenidae). For this species is proposed a new family — Fabesporidae. In the mucus from the surface of the bullheads' body of Proterorhinus are found infusoria Clausophrya oblida gen. et sp. n. characterizing by the presence of a peculiar fastening organella in the shape of a ring.

Summary is absent.