Archive

The age structure of Ixodes pavlovskyi natural populations from Novosibirsk and its outskirts was studied with the use of the fat reserves in the midgut and in the fat body as the age index.

A new technique for the study of the external morphology of thoracic sclerites of mosquitoes (Diptera: Culicidae) is elaborated. According to this method, the shape of sclerites and the location of setal and scale bases can be examined under a scanning electron or an optical microscopes even in cases when setae or scales are lost. The method can be recommended for the damaged material, as it often happens while sample collecting. The bases of setae differ significantly from those of scales in the size of the orifice in the socket. The diameter of setal bases usually exceeds 100 microns, while the diameter of scale bases is about 30 microns. The analysis of the structure of sclerites (and the disposition of setae and scales on the sclerites) taken from the different specimens of one species will allow describing intraspecific variations of the given complex of morphological characters. The comparison of species from different genera of family Culicidae, as well as the comparison of closely related species, will presumably help evaluating the diagnostic value of thoracic sclerites as morphological characters.

The results of the long-term studies of mosquitoes in Belgorod Province are given. The material has been collected from 54 localities situated in 15 districts of the province. Different biotopes were investigated during the spring-autumn period. Larvae and adult mosquitoes were used for the identification. A total of 27 mosquito species were revealed in the region examined. The following species were recorded for the first time: Ae. (Och.) communis, Ae. (Och.) diantaeus, Ae. (Och.) pulchritarsis, Ae. (Och.) sticticus and Cx. (Bar.) modestus. Cx. (Cux.) pipienspipiens biotype molestus was also mentioned from the region for the first time. The frequency of occurrence of each species in different biotopes and different localities is given. The most wide-spread and mass species in Belgorod Province include Ae. (Och.) cantans (Mg.), Ae. (Odi.) cataphylla Dyar, Ae. (Fin.) geniculatus (Ol.), Ae. (Adm.) vexans (Mg.), Cx. (Cux.) pipiens, and Cx. (Cux.) pipiens pipiens biotype molestus.

A new mite species of the genus Haemogamasus Berlese is described from the muskrat in Kyrgyzstan. Differential diagnoses of species of this genus from Kyrgyzstan are given.

Juvenile salmon Salmo salar m. sebago Girard from the Pista River system (the White Sea Basin) was investigated. The data on species composition and occurrence peculiarities of Gyrodactylus salaris Malmberg, 1957 are given. This monogenean is the alien species for the river system and it is recorded for the first time. It is shown that the distribution of the parasite abundance is can be described as the negative binomial distribution; variations of its parameters (k and p) were also characterized. Parasitological data obtained, as well as the data describing the characteristics of growth and age structure of juvenile salmon population, suggest the potential influence of G. salaris infection on the degree of survival of fishes in the lake-river system examined.

Data on trematodes of the order Plagiorchiida from 11 species of amphibians from the Middle Volga region are given. Literary data of the last 30 years, combined with the results of our own research are presented together for the first time. Finds of 17 trematode species are reliable. From them, metacercaria of Astiotrema monticelli is recorded from amphibians of the fauna of Russia for the first time; Dolichosaccus rastellus and Paralepoderma cloacicola are recorded for the first time from amphibians of the Middle Volga region. New hosts are mentioned for 8 species of parasites. Trematodes of edible frog Dolichosaccus rastellus and Paralepoderma cloacicola Linnaeus, 1758, a new species to the region, are described for the first time. The following characteristics are given for each trematode species: its taxonomic position, set of hosts, localization, places of detection, biology, geographical distribution, and the degree of host specificity. Morphological descriptions and original figures are given for 12 trematode species.

Mucoid glands of Cercaria baushii 6 (Xiphidiocercariae: Cercariae microcotylae Luhe, 1909) were examined. Gland cells differ from each other in the time of differentiation and in size. A brief sketch on the morphology of parthenites is also given.

---