Differences in the Bacterial Community of Laboratory and Wild Populations of the Predatory Mite Cheyletus eruditus (Acarina: Cheyletidae) and Bacteria Transmission From Its Prey Acarus siro (Acari: Acaridae).

Abstract

The parthenogenetic predatory mite Cheyletus eruditus (Schrank, 1781) is used for biological control against mite pests produced as CHEYLETIN. Although there is evidence that bacteria are mainly responsible for parthenogeny in several species of predatory mites, the description of association between C. eruditus the specific and parasitic or symbiotic bacteria is still missing. We analyzed the bacterial communities of the predator, C. eruditus , and its prey, Acarus siro L. The 16S rRNA gene was amplified, cloned, and sequenced. The selected bacterial taxa were confirmed by amplification of isolated DNA with taxon-specific primers. The 16S rRNA gene sequences from the predatory and prey mites formed a total of 20 different bacterial taxa. Of these taxa, the predator and prey shared four taxa, six taxa were specific for the predatory, and 10 taxa for the prey mites. Cardinium - and Bartonella -like bacteria were found in both mite species. The reproductive parasite Wolbachia was found only in the predatory mite, and A. siro hosted Solitalea -like (Sphingobacteriales) bacteria that were not detected in C. eruditus . We focused on Cardinium occurrence in the field samples of C. eruditus. Using Cardinium -specific primers, 128 clones were obtained. Cardinium was found in seven field samples of C. eruditus as well as in the laboratory population that was used to produce CHEYLETIN. Phylogenetic analysis of the Cardinium clones identified three separate clusters: two clusters showed high similarity to the Cardinium sequences from astigmatid mites, and one cluster contained only the clones from C. eruditus . Sequences of both Cardinium and Wolbachia were found in the both adults and eggs of C. eruditus , indicating maternal transfer of these endosymbiotic bacteria.