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Summary is absent.

The effect of parthenites and larvae of trematodes on the contents of total sugar, glucose as well as on the variations in the activity of acid and alkaline phosphatases of the haemolymph of Lymnaea stagnalis, Planorbis corneus and Viviparus viviparus has been studied. The studies have revealed differences in the degree of effect of individual species of parasites on their hosts depending on their localisation, infection intensity and developmental stage.

The life cycle of the trematode Plagioporus skrjabini has been investigated. These trematodes use the mollusk Theodoxus fluviatilis as the first intermediate host and sand hoppers as additional hosts (under experimental conditions — Pontogammarus robustoides, Chaetogammarus ischnus, under natural conditions — P. robustoides, P. crassus, Dikerogammarus villosus, D. haemobaphes, Ch. ischnus, Amathillina cristata). Bullheads (Neogobius kessleri, N. fluviatilis) serve as definitive hosts. Cercaria and metacercaria are described.

Diplostomosis is the most common disease affecting Coregonidae in lakes of Karelia where intensive fish farming is conducted. The most acute form of diplostomosis, cercariosis, is especially dangerous for larvae introduced into small water bodies. Depending on a season or weather conditions a shift in the infection rate of fishes with metacercariae takes place. Some ways for diplostomatosis prophylaxis are being suggested. Relatively shallow lakes with low miniralisation of water of sulphate type have been found to be most suitable for Coregonidae nurseries. The very specificity of the intensive use of lakes for fish farming offers possibilities for diplostomosis development. In lakes-nurseries with a regulated water regime the abundance of Lymnaeidae can be reduced by winter draining off the water. The chemical control of mollusks, local use of copper sulphate, is also possible under lake conditions.

The development of the cestode Khawia japonensis (Yamaguti, 1934) has been studied experimentally. At 18 to 26 С, in 12—14 days oncospheres develop in eggs, whose infective properties manifest themselves in 30—31 days. In the caudal segments of Limnodrilus udekemianus they penetrate the body cavity through the intestinal wall and migrate to the anterior margin as they mature. In 55 to 60 days (at the same temperature) mature procercoids become localized in 9—12 segments. The development of embryonal hooks and penetration glands was retraced.

131 specimens of 3 species of Galliformes from Vietnam were investigated (Gallus galius dom., G. g. jaboruillei, Francolinus pintadeanus and Lophora nycthemerus). In them 9 species of cestodes were found as follows: Davainea proglottina (Davainea, 1860), Cotugnia digonopora (Pasquale, 1890), Raillietina tetragona (Molin, 1858), R. echinobothrida (Megnin, 1880), Skrjabinia cesticillus (Molin, 1858), Paroniella tinguiana Tubangui et Masilungan, 1937, Amoebotaenia cuneata (Linstow, 1872), Echinolepis carioca (Magalhaes, 1898), Dilepidoides bauchei (Joyeux, 1924). In domestic hens there were found all 9 species of cestodes while in wild Galliformes — only 7, which are mentioned for them for the first time.

About 80 species of mermithids parasitic in blackflies have been recorded from the Ethiopian and Holarctic regions. Species of three genera, Mesomermis, Gastromermis and Isomermis, are most common parasites of blackflies. Critical periods during the ontogenesis of all mermithids are associated with the penetration of infective larvae into the host and protective reactions of the later. Intraspecific hybridization of the parasites is recommended in order to increase the effectiveness of mermithids as agents of biological control of blackflies.

Study of the morphology of 602 specimens of N. rutili (Müller, 1780) and N. crassus Van Cleave, 1919 collected in 10 species of fishes from waterbodies of the Kola Peninsular, the Ob, Yenisei, Lena, Kolyma and Chauna rivers has shown that all absolute specific characters considered (13 in ♀♀ and 17 in ♂♂) have a considerable range of variations due to the modificational individual and age variability. Differences have been revealed in morphometric indexes of some characters in members of the European and Siberian populations of N. rutili that is due to a geographic variability of the species. It has been established that most constant characters of all species studied are the length of the proboscis and its hooks.

A high abundance of C. p. pipiens and C. p. molestus in the town of Sukhumi and its vicinity was recorded from June to October. According to siphonal indexes the 4-th-stage larvae of these mosquitoes differ from each other rather insignificantly. The females of C. p. pipiens exhibit a high fecundity within a warm period of the year which sharply falls by the autumn. During a two-year experiment with a basement micropopulation of С. p. molestus from a non-autogenous form of C. pipiens there was established a gradual increase in the number of autogenous and stenogamic individuals. At the carbohydrate feeding the majority of the first autogenous females with ripe eggs are at the 3-rd—4-th stage of obesity.

11.501 ectoparasites of 45 species were collected from small mammals (rodents, shrews and double-toothed rodents) in the north-eastern part of Priamurje. The parasitecoenoses are formed in general by gamasid mites (60.4%) and lice (24.7%) but faunistically fleas (19 species or 42.2%) are dominant. Among all ectoparasites the gamasid mites, Laelaps clethrionomydis and Hirstionyssus isabellinus, and the louse Hoplopleura acanthopus account for 64.9%. The impoverishment of the arthropod fauna in the northern part of Priamurje as compared to southern ones proceeds at the expence of chigger mites and more thermophilous species of gamasids and ixodids. With cultivation of forests the content of members of parasitecoenoses becomes more homogenous and their abundance falls.

The paper presents data on the specific composition and abundance of bloodsucking arthropods parasitic on small mammals and birds in the valley of the Kamchatka river. One species of ixodids, I. lividus, 9 species of gamasids, P. crassipes, E. kraepelini, G. bispinosus, V. bujakova, H. casalis, H. mandschuricus, M. decoloratus, P. bujakovae, Macroheles sp., and one species of fleas, C. riparius, were first recorded from Kamchatka. 723 rodents were bacteriologically examined for tularemia with negative results.

A study of the morphology of the species Diplozoon inustiatus Nag., 1965 has revealed distinct differences of this species from other members of Diplozoidae. On this bases Diplozoon inustiatus has been accorded a status of a distinct genus, Inustiatus. The diagnosis of this genus and a redescription of the species I. inustiatus are given.

The concept of the exceptional peculiarity of the genital system structure of Faustula keksooni (MacCallum, 1918), on the basis of which this trematode was accorded a distinct status of the order Faustulata, is considered as erroneous one. The literary data on the reexamination of the holotype are given. The status of the parasite in the family Fellodistomidae is discussed.

Summary is absent.

Summary is absent.

Summary is absent.