[Cytogenetic analysis of the noxious bloodsucker Boophthora erythrocephala (Diptera: Simuliidae) from different geographic zones].

Boophthora erythrocephala is a widely spread species inhabiting both small polluted water-bodies and large rivers. Three populations from Samara region in Russia and from Donetsk and Chernigov regions in the Ukraine have been studied. Five populations of this species in Russia were described earlier (Polyanskaya, Tsapygina, 1968; Petrukhina, 1972).

[B chromosome polymorphism of blackflies (Diptera, Simuliidae) from the north-western region of Russia].

We have studied karyofonds of natural populations and B-chromosome morphology of 8 species of blackflies from the North-Western region of Russia: Odagmia ornata Mg., Hellichiella crassa Rubz., Simulium morsitans Edw.

[A new blackfly species Cnetha itelmenica sp. n. (Diptera: Simuliidae) from Kamchatka].

The description of a new species Cnetha itehnenica Chubareva et Yankovsky, sp. n. is given.

[Morphological diversity of centromere regions in polytene chromosomes of blackflies (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.

[Results of a karyological study of blood-sucking flies (Diptera: Simuliidae) of Armenia].

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.