Orthoflavivirus Lammi in Russia: Possible Transovarial Transmission and Trans-Stadial Survival in Aedes cinereus (Diptera, Culicidae)

In the last few years, there has been a dramatic increase in the number of discovered viruses that are transmitted by arthropods. Some of them are pathogenic for humans and mammals, and the pathogenic potential of others is unknown. The genus Orthoflavivirus belongs to the family Flaviviridae and includes arboviruses that cause severe human diseases with damage to the central nervous system and hemorrhagic fevers, as well as viruses with unknown vectors and viruses specific only to insects. The latter group includes Lammi virus, first isolated from a mosquito pool in Finland. It is known that Lammi virus successfully replicates in mosquito cell lines but not in mammalian cell cultures or mice. Lammi virus reduces the reproduction of West Nile virus during superinfection and thus has the potential to reduce the spread of West Nile virus in areas where Lammi virus is already circulating. In this work, we isolated Lammi virus from a pool of adult Aedes cinereus mosquitoes that hatched from larvae/pupae collected in Saint Petersburg, Russia. This fact may indicate transovarial transmission and trans-stadial survival of the virus.

Geographical and Tick-Dependent Distribution of Flavi-Like Alongshan and Yanggou Tick Viruses in Russia

The genus Flavivirus includes related, unclassified segmented flavi-like viruses, two segments of which have homology with flavivirus RNA-dependent RNA polymerase NS5 and RNA helicase-protease NS3. This group includes such viruses as Jingmen tick virus, Alongshan virus, Yanggou tick virus and others. We detected the Yanggou tick virus in Dermacentor nuttalli and Dermacentor marginatus ticks in two neighbouring regions of Russia. The virus prevalence ranged from 0.5% to 8.0%. We detected RNA of the Alongshan virus in 44 individuals or pools of various tick species in eight regions of Russia. The virus prevalence ranged from 0.6% to 7.8%. We demonstrated the successful replication of the Yanggou tick virus and Alongshan virus in IRE/CTVM19 and HAE/CTVM8 tick cell lines without a cytopathic effect. According to the phylogenetic analysis, we divided the Alongshan virus into two groups: an Ixodes persulcatus group and an Ixodes ricinus group. In addition, the I. persulcatus group can be divided into European and Asian subgroups. We found amino acid signatures specific to the I. ricinus and I. persulcatus groups and also distinguished between the European and Asian subgroups of the I. persulcatus group.

[English and Russian terminology for the thoracic skeletal structures of mosquitoes (Diptera: Culicidae): a critical review]

The authors analyze different names of thoracic skeletal structures in mosquitoes (Dip- tera: Culicidae), used by various authors (Kirkpatrick, 1925; Edwards, 1932; Stackelberg, 1937; Sazonova, 1958; Belkin, 1962a, b: Maslov, 1967: Gutsevich et al., 1970; Knight, Laffoon, 1970; McAlpine, 1981; Becker et al., 2010). In the abovementioned publications, a small number of skeletal structures, morphologically very important for the identification of species and genera of the family Culicidae, are denoted by multiple synonymic names, while certain completely different skeletal structures are represented under a single homonymous name. Duplicated synonymic names for thoracic sclerites, setae, and scales on sclerites considerably hamper the work of specialists determining species of the family Culicidae. In some cases, this fact results in erroneous diagnostics of species. We provide a detailed description of the thoracic morphology of mosquitoes, pointing to existing synonymic Russian and English names for each skeletal structure and also recommend the use of a single Russian term for each structure.

[A new technique for the study of thoracic sclerites of mosquitoes (Diptera, Culicidae) allowing correct identification of genera and species]

A new technique for the study of the external morphology of thoracic sclerites of mosquitoes (Diptera: Culicidae) is elaborated. According to this method, the shape of sclerites and the location of setal and scale bases can be examined under a scanning electron or an optical microscopes even in cases when setae or scales are lost. The method can be recommended for the damaged material, as it often happens while sample collecting. The bases of setae differ significantly from those of scales in the size of the orifice in the socket. The diameter of setal bases usually exceeds 100 microns, while the diameter of scale bases is about 30 microns. The analysis of the structure of sclerites (and the disposition of setae and scales on the sclerites) taken from the different specimens of one species will allow describing intraspecific variations of the given complex of morphological characters. The comparison of species from different genera of family Culicidae, as well as the comparison of closely related species, will presumably help evaluating the diagnostic value of thoracic sclerites as morphological characters.

[Three-dimensionality of the male genitalia shape and species identification in the mosquito genus Aedes Meigen, 1818 (Diptera, Culicidae)]

Significance of 3D-shape investigation of the mosquitoes male genitalia is shown by an example of species from the genus Aedes (Diptera, Culicidae). Differences between true 3D-shape of the male genitalia and traditional 2D pictures made as a result of the examination of balsam microscopic slides are revealed. Original descriptions of 3D-shape of coxites, claspettes, 9th tergal lobes, and proctiger of 30 species from the subgenus Ochlerotatus have allowed us to find new diagnostic characters, namely general 3D-shape of basal lobe of coxite, claspette filament, and some other structures.

[Synonyms of mosquitoes (Diptera: Culicidae) from Russia (literature review)]

Synonymy of the genera, subgenera, and species of the family Culicidae Meigen, 1818 from Russia is revised. More than 300 synonyms for 9 genera, 23 subgenera, and 105 species of mosquitoes are listed.

[On the taxonomic composition of mosquitoes (Diptera: Culicidae) of the world and Russian fauna (critical review)]

Critical analysis of the taxonomy problems in the mosquito family Culicidae has been carried out. Different conceptions on the family classification are considered in historical aspect. Debatable points of the systematics of tribe Aedini are expounded. Recommendations on the use of names of mosquito taxa and annotated checklist of the Culicidae species from the fauna of Russia are given.