[Morphological diversity of centromere regions in polytene chromosomes of blackflies (Diptera, Simulidae)]. / Morfologicheskoe raznoobrazie tsentromernykh raionov politennykh khromosom krovososushchikh moshek (Diptera, Simulidae).

Karyotypes of more than 120 species of 33 genera of the Palearctic blackflies (Simuliidae) were studied on squashed acetoorcein stained preparations of salivary gland polytene chromosomes in larvae. In the course of evolution of the family, a significant complication was noticed in the morphology of centromere regions of polytene chromosomes. In plesiomorphic species, centromeres are not pronounced morphologically and the general picture does not differ from that of other bands and interbands of the polytene chromosome. In species with apomorphic characters, a distinct precentromeric heterochromatin appears, whose manifestation is responsible for morphological diversity of centromere zones in polytene chromosomes. They are represented either by conspicuous slightly thickened heterochromatic bands or by large amplified blocks of heterochromatin or puff-like structure, being considerably extended as a result of despiralization of precentromeric heterochromatin. There are species, which more commonly lack chromocentre and their chromosomes are separated. Some other species have ectopic contacts between pricentromeric heterochromatin. In some species, this heterochromatin is organized as a compact chromocentre. This has been found only in representatives of southern latitudes, most frequently in evolutionarily young species with narrow specialization.

[Results of a karyological study of blood-sucking flies (Diptera: Simuliidae) of Armenia]. / Itogi kariologicheskogo izucheniia fauny krovososushchikh moshek (Diptera: Simuliidae) Armenii.

Karyotypes of 31 species of black flies belonging to 11 genera have been examined. The morphology of polytene chromosomes from salivary glands of larvae and mitotic chromosomes of gonads and ganglia have been studied. It was found that most species have 2n = 6, except the Eusimulium species, which have 2n = 4. Each species is characterised by a specific pattern of polytene chromosomes. It was found that widely spread species are polymorphic in heterozygous inversions and additional B-chromosomes. The use of karyological studies in taxonomic diagnostics of black flies, especially in the cases when species are similar morphologically, was shown to be expedient.

[Cytogenetic features of the blood-sucking blackfly Wilhelmia paraequina Puri (Diptera: Simuliidae) from Armenia]. / Tsitogeneticheskie osobennosti krovososushchei moshki Wilhelmia paraequina Puri (Diptera: Simuliidae) iz Armenii.

Three blackfly Wilhelmia paraequina populations of Armenia (rivers Debet and Megriget, channel Megri) were studied. 2n = 6: IS + IIL, IIS + IL, IIIS + IIIL. Cytological maps of polytene chromosomes were constructed. High inversion polymorphism (95.63%) was observed, with 2.6 inversions per individual. Three inversions proved to be associated with male development: Y1 was characterized by a combination of two heterozygous inversions, IIL-3 + IIL-1, while Y2 had another combination of heterozygous inversions, IIL-5 + IIL-3. The X chromosome had a standard homozygous IIL disk sequence. The populations were shown to be similar in autosomal polymorphism. A tendency for differentiation was observed with respect to frequencies and types of sex-linked inversions: the sex determination system was Y1X-XX in the Debet and Megriget populations and Y2X-XX in the channel (Megri) population. On the strength of these findings, one W. paraequina morphotype was assumed to involve two cytotypes, A (Debet and Megriget populations) and B (Megri population).

[Morphological and karyotypic analysis of five blackfly species of the genus Cnetha (Diptera: Simulidae): description of the novel species from the Dzhrvezhskii canyon in Armenia]. / Morfokariotipicheskii analiz piati vidov moshek roda Cnetha (Diptera: Simulidae) s opisaniem novogo vida iz Dzhrvezhskogo ushchel'ia Armenii.

Morphological and karyotypical features of a new blackfly species Cnetha akopi sp. n. from Armenia are described. Comparative analysis of the new species and four closely related endemic species from Caucasus is performed. Photographic maps of polythene chromosomes are provided.

[The morpho-karyotypic traits of 4 species of black flies (Diptera: Simuliidae)]. / Morfokariotipicheskie priznaki chetyrekh vidov moshek (Diptera: Simuliidae).

Karyotypes of four species of blackflies belonging to plesiomorphic superspecific taxa, Prosimulium pronevitshae, P. frontatum, Stegopterna richteri, Greniera dogieli have been studied. Structural peculiarities of polythene chromosomes of the salivary glands in older larvae have been analysed. Banding patterns of polythene chromosomes and descriptions of these karyotypes are given for the first time. Karyotypic features of the examined species are compared. Based on the comparative karyological analysis the differences between taxa and their possible relationships are revealed.

[Variability of the morphological traits in the blood-sucking black fly Odagmia caucasica (Diptera: Simuliidae)]. / Izmenchivost' morfologicheskikh priznakov krovososushchei moshki Odagmia caucasica (Diptera: Simuliidae).

Eleven morphometric and four qualitative features of larvae, as well as 6 morphometric parameters of pupae of Odagmia caucasica, which had been collected in 5 geographically remote regions of Armenia, have been studied. In this work besides absolute values of features we have used their ratios (indices) that shows forms and proportions of different organs. It was found, that larvae taken from Bzhni and Getashen had asymmetry of bilateral characteristics and that there were differences in the level of morphometric features variability; the latter fact is connected with sex and phase of the insect. Study of chronological variability of populations from Bzhni, Getashen and Martuni has revealed differences in the nature of distribution of features. It was shown that the rate of differentiation between geographically isolated populations fluctuated in the range from 20 (Getashen) to 33% (Amassiya). Differences in the qualitative alternative features and in the rate of microsporidium infection distinguish the differentiation of populations from Bzhni and Amassiya, which is caused by anthropogenic factor in Bzhni and by isolating landscape barrier in Amassiya. Species-specific morphometric features were discovered; these were the indices of proportions of larva ventral sclerite and of pupa respiratory filaments.

[An analysis of the morphometric traits of the pupae of 3 populations of Testisimulium kondici (Diptera: Simuliidae)]. / Analiz morfometricheskikh priznakov kukolok trekh populiatsii Testisimulium kondici (Diptera: Simuliidae).

In the pupae of three populations of Testisimulium kondici (Bar.) the variations of nine quantitative characters are determined. The discrepancies between these populations are analyzed. With the help of statistical indices the specific distinctions of one of the studied populations from two others, which are not essentially different, is established. Earlier (Kachvorian, 1989; Kachvorian and Tonoian, 1990) karyological and phenotypical differences between the larvae of these populations were found. Considering that the isolated population develops under anthropogenic influence a link between the above discrepancies and this influence is assumed to exist.

[Comparative karyological study of 2 close species of blackflies of the genus Eusimulium]. / Sravnitel'no-kariologicheskoe izuchenie dvukh blizkikh vidov moshek roda Eusimulium

The structure of polytene chromosomes in the salivary gland of two hard for distinguishing species Eusimulium montium Rubz. and E. gviletense alizadei Djaf. was studied. The comparative-karyologic analysis of the taxons showed many common features in their karyotypes: complete conjugation of the homologous chromosomes in the connection between the length and the arms of chromosomes. At the same time these species are well distinguished karyologically according to the two inversions of the homozigotic type in the chromosomes I and III, to the duplication in IIL, and to the deficiency of the telometric region in IIIL of E. montium. These readjustments are considered to be secondary which suggests E. gviletense alizadei to be phylogenetically older than E. montium.