[Comparison of nucleotide sequences of ribosomal DNA of the mosquito genera Aedes and Ochlerotatus (Diptera: Culicidae: Aedini)].

Morphological study allowed identifying 9 species of mosquitoes of the genus Ochlerotatus and 2 species of the genus Aedes. Sequencing of the rDNA region was performed for all these speciemens. The sequences of rDNA were the following: A. cinereus -868 bp, A. vexans--889 bp, Och. cantans--803 bp, O. excrucians--801 bp, O. euedes--794 bp, Och. cyprius--777 bp, O. diantaeus--758 bp, O. intrudens--817 bp, Och. punctor--783 bp, O. dorsalis--748 bp, O. species--767 bp. On average, the size of Aedes rDNA fragments exceeds rDNA of Ochlerotatus by 90-100 bp. The sequences are characterized by a high number of insertions and deletions, and also by point substitutions of nucleotides. It is important to notice that interspecific differences include not only different regions of the internal transcribed spacers, but also the conservative site which is represented by the 5.8S gene. Among four substitutions in this gene, one (C/A) represents the difference between Aedes and Ochlerotatus, the next (T/A) distinguishes A. cinereus from Ochlerotatus speciment and A. vexans, and two substitutions (A/C, T/G) testify the similarity between O. dorsalis and O. species and specimens of Aedes. Besides, two more deletions are typical for O. dorsalis and O. species. One deletion is com- mon, it distinguishes them from the other examined species, and another one is typical only for O. dorsalis. When analyzing morphological characteristics and comparing nucleotide rDNA sequences of O. species with the database, the similarity to O. caspius has been revealed. On the whole, phylogenetic relationships among Ochlerotatus species correspond to subdivision into groups based on morphological characters. Probably, examination of the larger number of specimens will change the morphological division into groups.