Endosymbiotic Wolbachia infection in solitary bee communities

Solitary bees play an important role as pollinators of crops and native flora. Certain species are utilized for orchard pollination, making them desirable for commercial use. Bees within the genera Megachile and Osmia are sold and shipped nationwide to supply these commercial demands. This flux of bees also means movement of their microbiota, including bacterial endosymbionts capable of manipulating host reproduction. To test for presence of these bacteria I used diagnostic PCR and 454-pyrosequencing to survey solitary bees for bacterial taxa previously documented to cause reproductive anomalies. Consistent with literature, the endosymbiont Wolbachia was abundant in these bees. Through sequencing the Wolbachia, I found distinct patterns of strain variation among groups of bees. There were 7different strains, infecting 3 bee families and multiple genera. Some Wolbachia strains were unique to particular bee species, whereas others were spread out across many species.  Multi-locus strain typing (MLST) allowed comparison to previously published strains of Wolbachia in solitary bees. These comparisons indicate there may be geographic structuring of Wolbachia infection in solitary bees, and alludes to horizontal transfer of infection through bee communities, although further research needs to be conducted to determine the mechanism of transfer. This poses large implications for translocation of bees, since congeners from different geographic locations are unlikely to share the same Wolbachia strain. This could be a problem when taking into account the potential reproductive anomalies that may result as a consequence of interbreeding.