Surveys for maternally-inherited endosymbionts reveal novel and variable infections within solitary bee species

Maternally-inherited bacteria can affect the fitness and population dynamics of their host insects; for solitary bees, such effects have the potential to influence bee efficacy as pollinators. We screened bee species for bacterial associates using 454-pyrosequencing (4 species) and diagnostic PCR (183 specimens across 29 species). The endosymbiont Wolbachia was abundant, infecting 18 species, including all specimens from the family Halictidae. Among commercially-supplied orchard bees (family Megachilidae), only 2/7 species were Wolbachia-infected, but one species showed variable infection among specimens. Two other maternally-inherited bacteria, Arsenophonus and Sodalis, were also detected, neither of which was fixed in infection frequency. Differential endosymbiont infection could potentially compromise fitness and reproductive compatibility among commercially redistributed pollinator populations. (C) 2015 Elsevier Inc. All rights reserved.