Symbiotic Wolbachia bacteria in coccinellid parasitoids: genetic diversity, horizontal transfer, and recombination / Bacterias simbióticas Wolbachia en parasitoides coccinélidos: diversidad genética, transferencia horizontal y recombinación

Parasitoids, which constitute about 25% of all insects and attack arthropods of virtually all taxa, are considered the most suitable vectors for horizontal transmission of the symbiotic bacterium Wolbachia among insects. The parasitoids studied in this article develop in the larvae and pupae of ladybirds. For the first time, Wolbachia was found in parasitic wasp species of the genus Homalotylus (Hymenoptera: Encyrtidae) and from the subfamily Tetrastichinae (Hymenoptera: Eulophidae). To characterize the Wolbachia strains, six bacterial housekeeping genes were examined and compared with previously published Wolbachia gene sequences. The same bacterial strains were found in all individuals of each species of parasitic wasps collected in different places and at different times, which indicates the absence of contamination and testifies to the heritability of the symbionts in the studied chalcids. No evidence was found that the parasitic wasps were infected with Wolbachia, identical to the symbionts of their ladybirds hosts. We found one Wolbachia strain, wHom-2, which is a product of bacterial recombination from unrelated insects, including ladybirds. The lack of correspondence between the molecular phylogenies of Wolbachia strains and mitochondrial DNA of their hosts indicates horizontal transfers of Wolbachia among parasitic wasps of the genus Homalotylus and from the subfamily Tetrastichinae.(AU)

Symbiotic Wolbachia bacteria in coccinellid parasitoids: genetic diversity, horizontal transfer, and recombination.

Parasitoids, which constitute about 25% of all insects and attack arthropods of virtually all taxa, are considered the most suitable vectors for horizontal transmission of the symbiotic bacterium Wolbachia among insects. The parasitoids studied in this article develop in the larvae and pupae of ladybirds. For the first time, Wolbachia was found in parasitic wasp species of the genus Homalotylus (Hymenoptera: Encyrtidae) and from the subfamily Tetrastichinae (Hymenoptera: Eulophidae). To characterize the Wolbachia strains, six bacterial housekeeping genes were examined and compared with previously published Wolbachia gene sequences. The same bacterial strains were found in all individuals of each species of parasitic wasps collected in different places and at different times, which indicates the absence of contamination and testifies to the heritability of the symbionts in the studied chalcids. No evidence was found that the parasitic wasps were infected with Wolbachia, identical to the symbionts of their ladybirds hosts. We found one Wolbachia strain, wHom-2, which is a product of bacterial recombination from unrelated insects, including ladybirds. The lack of correspondence between the molecular phylogenies of Wolbachia strains and mitochondrial DNA of their hosts indicates horizontal transfers of Wolbachia among parasitic wasps of the genus Homalotylus and from the subfamily Tetrastichinae.

Three new taxa of the genus Cechetra Zolotuhin Ryabov, 2012 (Lepidoptera, Sphingidae) from South-East Asia with notes on other species of the genus.

Two new species and one subspecies of the genus Cechetra Zolotuhin Ryabov, 2012 are described from South-East Asia. Cechetra bryki sp.n. is described from Nepal, Myanmar (Burma), southwestern China and northern Vietnam. This species is most closely related in habitus, male genitalia morphology and COI mtDNA to the sympatric species, C. lineosa (Walker, 1856) and C. scotti (Rothschild, 1920) in habitus, male genitalia morphology and COI mtDNA. Cechetra inconspicua sp.n. is described from Peninsular Malaysia, Borneo and Sumatra. In habitus, it is closest to C. lineosa and C.subangustata (Rothschild, 1920), but its COI mtDNA (COI-5P "barcode region") is very different from all other species in the genus. Cechetra subangustata continentalis ssp.n. is described from continental Indochina and Taiwan. It differs from the nominotypical subspecies in habitus. Cechetra scotti comb. nov. is transferred to Cechetra from Cechenena Rothschild Jordan, 1903.

Spiroplasma infection in Harmonia axyridis - Diversity and multiple infection.

The heritable endosymbiotic bacterium Spiroplasma is found in the harlequin ladybird Harmonia axyridis. The proportion of beetles infected with Spiroplasma in different native H. axyridis populations varies from 2% to 49%. We investigated the polymorphism of Spiroplasma strains in samples from individual beetles from Kyoto, Vladivostok, Troitsa Bay, Novosibirsk, and Gorno-Altaisk. To identify Spiroplasma strains, we analyzed nucleotide polymorphisms of the 16S rRNA gene and the ribosomal internal transcribed spacer (ITS1). The majority of infected beetles were infected with two or more Spiroplasma strains. We measured Spiroplasma density in beetles with different infection status using quantitative PCR. The abundance of Spiroplasma in samples with a single infection is an order of magnitude lower than in samples with multiple infections. Density dependent biological effects of Spiroplasma are discussed.