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The criterions for two most used intraspecific taxonomic ranks of ticks — subspecies and morphotype, have been formulated on the basis of the study of morphological variation in the distribution range of all active ontogenetic stages of 11 polymorphic species. All these species are vectors of transmissible diseases. They have vast distribution ranges and different types of host-parasite relationships. Subspecies have the complexes of visual morphological differences expressed in one or both sexes of mature ticks more limited, than those of related species. At immature stages differences of subspecies consist more often in morphometry characters and can be established by the methods of mathematical statistics only. Morphotypes, as a rule, differ at each corresponding stage by "their own" complexes of morphometric characters. All differential parameters of studied morphotypes are overlapped, but have statistically significant differences (by the Student's test). The concrete variations of differentiation by subspecies and morphotypes have been considered. The historical factors of intraspecific differentiation have been reconstructed for each species.

The external morphological adaptations to parasitism in acariform mites (Acari: Acariformes), permanently parasiting mammals, are briefly summated and analyzed. According to several external morphological criteria (structures of gnathosoma, idiosoma, setation, legs and life cycle), the following six morphoecotypes were established: skin mites (i) — Cheyletidae, Chirorhynchobiidae, Lobalgidae, Myobiidae, Myocoptidae (the most part), Rhyncoptidae, Psoroptidae; fur mites (ii) — Atopomelidae, Clirodiscidae, Listrophoridae, Myocoptidae (Trichoecius only); skin burrowing mites (iii) — Sarcoptidae; intradermal mites (iv) — Psorergatidae and Demodicidae; interstitial mites (v) — Epimyodicidae; respiratory mites (vi) — Ereynetidae, Gastronyssidae, Lemurnyssidae, Pneumocoptidae. In the case of prostigmatic mites, the detailed reconstruction of the origin and evolution of "parasitic" morphoecotypes is possible due to the tentative phylogenetic hypotheses, which were proposed for the infraorder Eleutherengon, a, including the most part of the permanent mammalian parasites among prostigmatic mites (Kethley in Norton, 1993; Bochkov, 2002). The parasitism of Speleognathinae (Ereynetidae) in the mammalian respiratory tract arose independently of the other prostigmats. It is quite possible that these mites switched on mammals rom birds, because they are more widely represented on these hosts than on mammals. The prostigmatic parasitism on mammalian skin seems to be originated independently in myobiids, in the five cheyletid tribes, Cheyletiellini, Niheliini, and Teinocheylini, Chelonotini, Cheyletini, and, probably, in a cheyletoid ansector of the sister families Psorergatidae—Demodicidae (Bochkov, Fain, 2001; Bochkov, 2002). Demodicids and psorergatids developed adaptations to parasitism in the skin gland ducts and directly in the epithelial level, respectively in the process of the subsequent specialization. Mites of the family Epimyodicidae belong to the phylogenetic line independent of other cheyletoids. These mites possess the separate chelicerae and, therefore, can not be included to the superfamily Cheyletoidea. It is not quite clear whether they were skin parasites initially or they directly switched to parasitism from the predation. The phylogeny of sarcoptoid mites (Psoroptidia: Sarcoptoidea) is not developed, however, some hypotheses about origin and the following evolution of their morphoecotypes can be proposed. We belive that astigmatic mites inhabiting the mammalian respiratory tract transferred to parasitism independently of other sarcoptoids. The idiosoma of these mites is not so much flattened dorso-ventrally and has proportions which are similar to hose of free-living astigmatids. Moreover, in the most archaic species, the. legs are not shortened or thickened as in the most parasites. The disappearance of many morphological structures in these mites, probably, happened parallely with some other sarcoptoids due to their parasitic mode of life. The skin inhabiting sarcoptoids belong to the "basic" morphoecotype, and all other sarcoptoid morphoecotypes, excluding respiratory mites, are derived from it. Some mites of this morphoecotype live on the concave surfaces of the widened spine-like hairs of the rodents belonging to the family Echimyidae (mites of the subfamily Echimytricalginae), in the mammalian ears (some Psoroptidae) or partially sink into the hair follicles (Rhynocop-tidae). Finally, mites of the family Chirorhynchobiidae live on the bat wing edges attaching to them by their "ixodid-like" gnathosoma. The fur-sarcoptoids, probably, originated from the skin mites. This morphoecotype is divided onto two subtypes: mites with the dorso-ventrally flattened idiosoma (subtype I) and mites with the teretial idiosoma (subtype II). Each "fur-mite" family includes mites of the both subtypes. All mites of the first subtype belong to the early derivative lineages in their families. Among listrophorids such early derivative lineage is represented by the subfamily Aplodontochirinae (Bochkov, OConnor, 2006), and among Chirodiscidae — by mites of the subfamilies Chirodiscinae, Schizocopti-nae, and Lemuroeciinae. Among the "fur" astigmatid families, the family Atopomelidae. probably, is the most archaic, and the most part of atopomelids belongs to the first subtype. However there are several more specialized atopomelid genera belonging to the second subtype, Atopomelus, Dasyurochirus, Lemuroptes, Murichirus, Metachiroecius etc. We believe that mites of the first subtype are represented by the "intermediate" forms between skin mites and mites of the second subtype. Some skin sarcoptoids transferred from skin parasitism to burrowing of the host skin (Sarcoptidae). The established morphoecotypes are partially corresponding to some morphoecotypes established by Mironov (1987) for feather mites. Our morphoecotypes of skin and skin burrowing mites perfectly correspond to Mironov's epidermoptoid and knemidocoptoid morphoecotypes, respectively. The proctophylloid morphoecotype (mites living on the wing feathers), which is the most widely represented within feather mites, has an analogy among mammalian mites — the subfamily Echimytricalginae. The analgoid (mites living in the down feathers) and dermoglyphoid (mites living in the feather quills) morphoecotypes have no analogues among mammalian mites for the obvious reasons. It is interesting why some microhabitats on the host body are not still occupied by prostigmatic or astigmatic mites. We believe that the nutrition is the main limitative factor here. The parasitic prostigmates evolved from predators and, therefore, feed on content of the living cells. They need the direct contact with the live tissues of the host and they belong, therefore, to the morphoecotypes represented by the respiratory, skin, gland duct, intradermal, and interstitial mites. Whereas, the most part of the skin inhabiting astigmats feed on the dead epithelial scales. For this reason these mites, so easily colonized fur of their hosts and feed on the hair grease there. On the other hand, some sarcoptoids transferred to the true parasitism and feed on the cambial cells of the skin epithelium. More over we do not know exactly about nutrition of rhyneoptids yet.

In 2004 June—July collections of mosquito adults and small mammals were carried out in two areas of Novosibirsk Region (forest-steppe and steppe zones), where the West Nile vims (WNV) was for the first time recorded in birds with different migration status in 2002—2004. Seventeen species of mosquitoes were found; significant changes in their species composition and abundance, as compared with latest faunistic studies made in the sixtees-seventees of the last century, are revealed. WNV markers (antigen, RNA) are found in small mammals; highly sensitive to the WNV replication mosquito species are also found. These facts allow supposing a possibility of the formation of stable West Nile virus natural foci in the South of Western Siberia, under conditions of forest-steppe and steppe zones.

An ecological-faunistic analysis of mosquitoes has been carried out in the Strezhevoy town (Tomsk Region). Thirty-one species of mosquitoes have been recorded in the territory examined. The population peak of mosquitoes is recorded in the 1—2 ten-days of July. Characteristics of the biotopic distribution and daily activity of the dominant mosquito species are revealed. Limiting factors of daily activity of mosquitoes in the investigated territory are characterized.

Phylogenic models for each aphelenchid family and phylogeny of the order Aphelenchida as a whole were developed on the base of detailed comparative morphological and bionomical analysis of the order. Bionomical and morphological characters having a phylogenetic significance were selected. Classification proposed by Hunt, 1993 was used as the starting-point of the study. Life cycles and their evolution in Aphelenchida were analyzed on the base of phylogenetic trees. It is concluded, that aphelenchid ancestors combined mycophagy, plant parasitic, and partly predaceous feeding. Relations of the primitive Aphelenchida with their sym-bionts developed from the spots of the fungal organic matter decomposition in the "nematode-fungi" associations, followed by a transition to the temporary endoparasitic habit omitting ectoparasitism. With a complication of the nematodes' life cycles, the insect vector (detritophagous or pollinator) transformed into the real insect host of the parasitic nematode in the 2-host life cycle (with the plant and insect hosts) or in the obligate 1-host entomoparasitic life cycle of the aphelenchid nematodes. Specialization of the aphelenchid life cycles to insect vectors followed two main ways. In the first way, the resistant to unfavorable environmental conditions nematode juveniles, known already for the primitive aphelenchids transformed into dispersal juveniles, and later into parasitic juveniles. In the second evolution line the dispersal function were laid on inseminated but non-gravid (not egg-producing) females. Both above-mentioned trends of parasitic specialization were arisen independently in different phylogenetic lines of the Aphelenchida. In each line of the parasitic development in different nematode families, the highly specialized ectoparasites, as well as endoparasites on insects, were formed. In the evolution of life cycle of parasitic nematodes, a tendency to decrease the body size took place. The function of dispersion shifted to more junior juvenile stage (the first line of specialization), or body sizes of non-gravid females and males copulated with the latter become smaller (second specialization line, till the development of dwarf males and location of the males and small inseminated non-gravid females in the uterus of gravid nematode female). The hypothetic fundamental model of the parasitic cycles' specialization in the order Aphelenchida was developed, basing on the comparison of known life cycles in different phylogenetic lines within aphelenchid families. The conception of the geographic origin and historic dispersal of the order Aphelenchida was proposed. The origin of the superfamily Aphelenchoidoidea and order Aphelenchida as a whole probably took place in eastern areas of Gondwana (parts of which are recently Hindustan, Indo-Malaya, Australia and Antarctica), presumably in the Devonian period. When the Gondwana and Laurasia paleocontinents were joined into Pangea in Carbon period, aphelenchids dispersed in the Laurasian part of Pangea. Endemism of the advanced entomophilic ectoparasitic Acugutturidae indicates on the secondary hotbed of speciation in Caribbean area. Development of the anhydrobiotic adaptations in the Aphelenchida promoted their successful invasion in the cold regions of Holarctic. Another important adaptations was the transformation of the initially resistant nematode life cycle phase into the dispersal phases vectored by insects.

Dynamics of the reproduction in the trematode Echinostoma caproni parthenites (Echinostomatidae) was observed. Early laying and maturation of the generative cells are for the first time shown to be characteristic for all parthenogenetic generations. Really the process of reproduction had been finishing to the beginning of the generating of new age by parthenites. Mother sporocysts, as well as redia of different generations, in fact stop producing new generative cells with the beginning of the generating of new age, and assume the function of a brood pouch. This feature was considered previously as peculiar mainly to mother sporocysts. Data on the autotomy of the anterior body end in mother sporocysts are verified. In our opinion, these data are an evidence of an early manifestation of the evolutionary trend to the morpho-functional regress and disintegration of the parasitic stage of mother sporocyst.

Dynamics of abundance and changes of populations structure were investigated in a host specific parasite of salmonids, cestode Proteocephalus longicollis from the vendace Coregonus albula L., of the Syamozero Lake during the period of more than forty years. A relative stability of the values of infestation indices independently of significant changes in the abundance and population structure of the vendace is established. Changes in the distribution of abundance and population structure of P. longicollis are shown to be connected with the change of the water body's status resulting from eutrophication. These changes can be considered as reliable indices of the succession in freshwater bodies.

Summary is absent.