[Cytogenetic Analysis of the Species Composition and Inversion Structure of Populations of Malarial Mosquitoes in the Astrakhan Region].

A cytogenetic analysis of Anopheles mosquitoes in the Astrakhan region was carried out. Three species of Anopheles were identified. An. messeae lives everywhere and prevails in all of the areas of research, An. hyrcanus is found in the southwest of the region, and An. maculipennis in the northern part of the region. The populations of An. messeae show a high level of inversion polymorphism for the sex chromosome and the third autosome. A clear clinal trend of an increase in chromosomal rearrangements XL1, 3R1, and 3L1 and a decrease in the frequency of evolutionary source alternatives was revealed in laraval hemipopulations of the species from south to north.

[Genetic aspects of sexual behavior in malaria mosquitoes on the basis of specific acoustic signals at mating].

Acoustic characteristics were studied in two species of the "Anopheles maculipennis" species complex, A. messeae and A. atroparvus. The species were found to clearly differ in sound frequencies, which was assumed to play a key role in species identification during mating in regions of their sympatric distribution. The sound spectrum in A. messeae was far more diverse than in A. atroparvus, which was associated with intraspecific inversion polymorphism of the former. Mosquitoes with the inversion combinations that were most common in populations of the central region of the A. messeae species area specifically differed in acoustic signal spectrum from each other. Hence, sound communication within the species was considered to be the main mechanism that is responsible for sexual partner selection and determines the chromosome associations observed earlier in individual karyotypes. Since males carrying different inversion combinations significantly differed in acoustic characteristics, females were assumed to play a main role in selecting the sexual partner.

[Inversion polymorphism and ecological specialization of malaria mosquitoes (Diptera, Culicidae) in Karelia].

The species composition and inversion polymorphism were studied in malaria mosquito larva hemipopulations of Karelia. Three malaria mosquito species--Anopheles messeae, A. beklemishevi, and A. maculipennis--were found in the region. The northern boundary of their range is at 65 degrees NL. The greatest species diversity was observed in biotopes of the central region. Within-species chromosome polymorphism was observed in larva populations of all three species. For A. messeae, maximum karyotype diversity indices were established for the southern and northern regions of Karelia.

[The population-and-species-specific structure of malaria (Diptera, Culicidae) mosquitoes in the Caspian Lowland and Kuma-Manych Hollow].

The authors studied the population-and-species-specific structure of malaria mosquitoes in the Caspian Lowland and Kuma-Manych Hollow (Republic of Kalmykia, Stavropol Territory). Five Anopheles mosquito species were identified. An. messeae and An. atroparvus were dominant; An. maculipennis, An. hyrcanus, and An. sacharovi were ecologically specialized and relatively rare. An. sacharovi was first found in Kalmykia, which is the most dangerous malaria vector in the south regions of the CIS. This allows the former known borders of its area to be expanded to the northwest Paleartics. An. messeae showed a high rate of inversions along both arms of chromosome 3 in homo- and heterozygous states, as well as a unique inversion in sex chromosome. The An. atroparvus population in the region was found to have a high rate of inversion on the 3L arm, which had been previously recognized as rare in Ukraine only.

[Chromosome polymorphism and regularities of the subpopulation organization of malaria mosquitoes Anopheles (Diptera, Culicidae) in biotopes of the Tomsk oblast].

A biotopic subdivision was observed for the two closely related species Anopheles messeae and A. beklemishevi in larval biotopes of the Tomsk oblast. The regularities of the spatial distribution of A. messeae with various chromosomal inversions were determined. The A. messeae karyotypic structure proved to vary depending on the ecological conditions of wintering and reproduction sites. The frequencies of chromosome variants XL0, 2R0, 3R0, and 3L0 were maximal in villages, while forest biotopes were characterized by elevated frequencies of alternative inversions. A comparison of the chromosomal structure for larvae and adults confirmed the subdivision of spatial niches for adults with different karyotypes. The difference in spatial niches was assumed to reflect the ecological specialization of mosquitoes. At the interspecific level, such specialization allows closely related species to occur in sympatry regions. At the intraspecific level, a subdivision of spatial niches reduces the intraspecific competition, increases the population size, and improves the survival during unfavorable periods associated with changes in abiotic factors.