Archive

The first parasitological division in the Zoological Museum was created in 1924 by the initiative of E. N. Pavlovsky and A. A. Schtakelberg and originally had a named "The permanent commission on the study of malaria mosquitoes". In the process of reorganisation of the Zoological Museum into Zoological Institute in 1930, it was modified into the Department of Parasitology with the E. N. Pavlovsky as a head. In 1934—1935, two laboratories were formed within this department: the Laboratory arachno-entomology and Laboratory of parasitic worms. In subsequent history of ZIN, these parasitological laboratories existed at first as subdivisions of the Department of Parasitology and finally the they were reorganised into independent administrative divisions. The study of parasitic and blood-sucking arthropodes is concentrated in the Laboratory of Parasitology (the head Yu. S. Balashov). A creation of the most important concepts of ecological parasitology was taking place in the Zoological Institute in the middle of 30th. E. N. Pavlovsky for the first time had formulated the principle of an organism as an environment for parasites, the concept of communities of parasitic organisms (concept of parasitocoenosis), and the theory of natural focuses of transmissive diseases. In the process of development of these scientific generalisations, a scientific direction named "Academician E. N. Pavlovsky's school of thought in parasitology" was formed in the USSR in 40—50th. In the frame of this school of thought, the main tusks of the Laboratory of Parasitology ZIN are to work out fundamental problems in ecology, systematics and morphology of parasitic and blood-sucking ticks, mites and insects. Within the ecological parasitology, different aspects of host-parasite relationships are studied at organism and population levels. The main basis of systematics studies of parasitic arthropodes is a scientific collection including over 250.000 samples. Based on this material, 40 key books and monographs on the USSR's fauna were created. Over 20 doctors of science and 50 candidates of science have been prepared within the laboratory or under the promotion of its stuff during 70 years of the existence of the Laboratory of Parasitology.

Species status is stated for Hyalomma anatolicum and H. excavatum, based on numerous material from the territory of their distribution. The differentiation of species is recovered for all stages of the life cycle. Diagnosis of Hyalomma anatolicum. Female: small tick — length of scutum commonly less than 2 mm; width of scutum commonly less than 1.9 mm; color of scutum, gnathosoma and coxae light, yellowish- or reddish-brown; whitish enameled pigment on scutum absent; posterolateral ledges of scutum weakly expressed or absent; cervical and lateral grooves more shallow (than in H. excavatum) (fig. 1); setae of scutum, alloscutum, sternal setae and ventromedian setae of second article of palpae more tapering to the apex, narrow rounded or acute (fig. 2, 1, 2, 5, 8). Male: small tick — length of conscutum, as a rule, less than 4 mm; width of scutum, as a rule, less than 2.3 mm; shape of conscutum narrow oval (fig. 3), widest in the midlevel; color of conscutum, anal shields, gnathosoma and coxae light, yellowish- or reddish-brown; whitish enameled pigment on conscutum absent; caudal depression with less dense and more large punctuations (than in H. excavatum); ridges lateral to caudal field less high and sharp (than in H. excavatum); posteromedian groove separated from parma by contiguous punctuations or smooth non high area; setae of conscutum conus-like, more sharpening (fig. 4, 1—3); posterior dorsal margin of gnathosoma straight or slightly concave (fig. 4, 8); segments of leg IV not swallowed. Nymph: large tick (see description). Scutum more narrow. Dorsal tale of spiracular plates clear expressed, marginal perforations distanat from margin of spiracular plates at the base of tale (fig. 5, 3); anterolateral side of basis capituli approximately equal to half of gnathosoma width; ventrally lateral projections of gnathosoma situated in posterior half of capitulum base (fig. 5, 4, 5). Hypostome more longer and narrow (fig. 5, 5). Larva: large tick (see description). Diagnosis of Hyalomma excavatum. Female: large tick — length of scutum commonly more than 2 mm; width of scutum commonly more than 1.9 mm; color of scutum, gnathosoma and coxae dark, reddish- or black-brown; whitish enameled pigment commonly present; posterolateral ledges of scutum clearly expressed; cervical and lateral grooves more dipper (than in H. anatolicum) (fig. 7). Setae of scutum, alloscutum, sternal setae and ventromedian setae of second article of palpae more stick-like, more widely obtuse (fig. 8, 1—5). Male: large tick — length of conscutum more than 4 mm; width of scutum more than 2.3 мм; shape of conscutum wide oval (fig. 9), widest in posterior half of length; color of conscutum, anal shields, gnathosoma and coxae dark, reddish- or black-brown; whitish enameled pigment often present; caudal depression with more dense and more small punctuations (than in H. anatolicum); ridges lateral to caudal field more high and sharp (than in H. anatolicum); posteromedian groove separated from parma by strong elevations fused with paraparmal festoons; setae of conscutum more obtuse, often stick-like (fig. 10, 1, 2); posterior dorsal margin of gnathosoma straight or lightly concave, (fig. 10, 3); segments of leg IV swallowed. Nymph: small tick (see description). Scutum more wide. Dorsal tale of spiracular plates weakly expressed, marginal perforations not distant from margin of spiracular plates at the base of tale (fig. 11, 3); anterolateral side of basis capituli clearly shorter than half of gnathosoma width; ventrally lateral projections situated in the middle of or anterior half of capitulum base (fig. 11, 4, 5). Hypostome more shorter and wider (fig. 5, 5). Larva: small tick (see description). Established taxonomical independence of H. anatolicum and H. excavatum is confirmed by several criteria: external morphology (see diagnoses); morphometrical data (see diagnoses and fig. 12, 13); size inversion: larva and nymph of H. anatolicum are large, but females and males are small; while H. excavatum vise versa — larva and nymph are small, but adults — large; host specialization of immature stages: larvae and nymphs of H. anatolicum, as rule, parasitize larger mammals (cattle, camels), while immature stages of H. excavatum parasitize smaller mammals (rodents, hares); presence of sympatry areas: almost entire area of H. excavatum include in area of H. anatolicum and cattle help to mix its populations.

Intraspecific variability in three closely related chigger mite species of the genus Hirsutiella Schluger et Vysotzkaya, 1970, H. steineri (Kepka, 1966), H. llogorensis (Daniel, 1960), and H. alpina Stekolnikov, 2001 has been studied based on materials collected in Caucasus and Turkey. It is established that both H. steineri and H. llogorensis include Western Caucasian and Asian forms, the first one being larger than the second one. Western Caucasian samples of H. steineri are also split into large and small forms. The large form inhabits screes with larvae occurring mainly on snow voles, and the small form inhabits meadows and forests with larvae parasitizing snow voles as well as mice of the genus Apodemus and pine voles. Asian population of H. steineri include small low-mountain form which is hard to distinguish from H. llogorensis. In the light of the new data on variability, morphological border between these two species are specified. Correlations between some characters and altitude above sea level are shown within the Western Caucasian and Asian forms of both species, and also in H. alpina. All the three species can occur together on the same individual hosts, but they have different sets of main hosts and different distribution among biotopes in the area of sympatria. The border between H. steineri and H. llogorensis in the places of sympatria can be indistinct owing to the presence of small ecological forms of H. steineri. Our results give a basis for the construction of alternative hypotheses concerning the processes of speciation in trombiculids. Chiggers species could be formed in allopatric way, on the base of such geographical forms, as Western and Asian forms of the Caucasian Hirsutiella species, but they could also be formed in sympatric way, distributing among neighbouring biotopes (e.g., screes and meadows, or screes and forests), as large and small forms of Western Caucasian H. steineri do.

The lists of malaria mosquitoes in Russia includes 12 species, rather than 13, as it was formerly considered (Gornostaeva, 2000; Gornostaeva, Danilov, 2002), because Anopheles subalpinus is a junior synonym of An. melanoon. Data accumulated up to present are still not sufficient to characterize ranges of many species in Russia, specifically An. beklemishevi, An. maculipennis, and An. messeae. Careful investigations of biodiversity and ranges of the malaria mosquitoes in different territories of Russia have not been carried out since 40—60th. In the last 50 years, a cytodiagnostic method appeared to be the most perspective method for the study of biodiversity and ranges of the malaria mosquitoes in Russia. Critical analysis of data obtained by this methods shows that the studies of biodiversity and ranges of the malaria mosquitoes should be performed in a contact of entomologist and genetic experts to avoid errors in a collection of field data and laboratory tests. The study of biodiversity and ranges of the malaria mosquitoes is a quite important field of investigations, because of increase of local cases of the malaria disease and unfavorable prognosis for nearest years in relation to the malaria.

The cestodes Bothriocephalus scorpii during the incubation in vitro assimilated glucose from the incubation medium and synthesized of glycogen. End products of carbohydrate metabolism in B. scorpii were lactic, succinic and volatile fatty acids. Mitochondria isolated from B. scorpii intensively oxidized succinate, α-ketoglutarate, isocitrate and less intensilevy oxidized citrate, oxalacetate, pyruvate, cis-aconitate and malate.

Pathological alterations being similar to those that can be seen while hormonal disbalance, particularly the increase of juvenile hormone (JH) titre, is one of the consequences of microsporidian infections. Though the increase of JH in insects infected with microsporidia has not been shown directly, there are many indirect proofs of this. It has been believed that JH is produced by microsporidia. But this has not been shown for microsporidia or for other endoparasites. In this article we want to propose another hypothesis. We suppose that during microsporidiosis the following events develop: exhaustion of host nutrition stores and other destructive consequences of microsporidian dwelling in host cells lead to the decrease of host biosynthetical and reparation activity in the infected cells and then to destructive alterations that can be seen by electro-microscopic methods. The infected cells are stressed and then the typical answer for many physiological stresses follows. Secretion of prothoracicotropic hormone by brain neurosecretory cells is inhibited and as a result the production and release of ecdysone is also inhibited and ecdysteroid titre decreases. The activity of JH-esterases is decreased and as a result the JH titre is increased. If microsporidian infection causes the stress in the host cells, the endocrine system will undoubtedly answer to this stress and this answer will definitely be the same as for all other stresses. Thus, in any case JH titre will be increased in infected insects independently of whether microsporidia produce JH or not. So, hormonal alterations in infected insects should be the consequence not of the microsporidian JH production but of the host response reaction to infection. We suppose that microsporidia do not differ from other parasites of insects and that they can not produce JH.

The isosporan-type of oocysts is a later evolutionary purchase in comparison with the eimerioran-type construction of oocysts'. Identical number of sporocysts and sporozoits in the oocysts, bivalvular constructions of sporocysts, heteroxenous life cycles and endogenous sporulation in a group series of coccidia have arisen asynchronously and independently. The evolution of RNA genes and a type of oocysts construction was proceeded in different species of the isosporan-type coccidia and with different velocities.

Some differences in trehalose catabolism were found for terrestrial and aquatic microsporidian species (Undeen, Van der Meer, 1999). In microsporidia species from aquatic hosts, the spore extrusion causes the intrasporal trehalose hydrolysis by trehalase that is followed by the drastic rise of reducing sugars (glucose) concentration. On the contrary, in tested terrestrial microsporidian species, total and reducing sugars remain unchanged through the germination. In this study we demonstrate by means of the enzymatic and paper chromatography methods, that in spores of microsporidia Nosema grylli, infecting fat bodies of crickets Gryllus bimaculatus, neither an increase of glucose concentration nor a reduction in intrasporal trehalose content takes place during the spore discharge. In this respect N. grylli is close to other terrestrial species. However, we have revealed in N. grylli spores activity of α,α-trehalase (EC 3.2.1.28) with acid pH-optimum like it was found by other authors in spores of aquatic microsporidia N. algerae. This result differs from the neutral pH-optimum (7.0) of trehalase of other terrestrial microsporidia N. apis. Concentration of trehalose in N. grylli spores reduces during long-term storage. All attempts to detect an activity of trehalose phosphorylase (synthase) (КФ 2.4.1.64), other potential key enzyme for trehalose catabolism in N. grylli spores have failed. The absence of changes of the sugar content in terrestrial microsporidian spores during the extrusion indicates, that the main physiological role of trehalose hydrolysis by trehalase in these species is catabolism of energy reserves for providing the long-term survival in the environment.

Drawings, description and size characteristics are given for Tetraonchus awakurai, which is registered for the first time from Brachymystax tumensis in the Ussury river (Primorye). The T. awakurai from the Ussury river differs from the typical forms living in water reservoirs of Japan by the measurements of external and internal lengths of anchors and copulatory complex.

Description of a life cycle and development stages of a trematode Holostephanus nipponicus Yamaguti, 1939 is given. Experimental studies have shown that in Primorye, the first intermediate host is commonly a snail Parafossarulus spiridonovi, and the second hosts are freshwater fishes Rhodeus sericeus sericeus and Pseudorasbora parva. Adult worms H. nipponicus were reared in a chicken.