Bacteria belonging to the genus Bacillus associated with three species of solitary bees

Brood provisions from Centris flavofasciata and Xylocopa californica arizonensis, larval feces and pollen collected by X c arizonensis, and the alimentary canal of adult female Crawfordapis luctuosa were examined for micro-organisms, particularly spore-forming bacteria belonging to the genus Bacillus. Bacillus species were associated with some samples from all 3 bees. Brood provisions of C flavofasciata contained B licheniformis. Bacillus cereus, B subtilis, and an unidentified Bacillus similar to B sphaericus were isolated from the gut of Crawfordapis. Pollen collected by X c arizonensis contained B circulans, B pumilus, and B subtilis. The latter species was also associated with provisions of a young carpenter bee larva. These results and our previous findings on microflora of Anthophora sp, Apis mellifera, Centris pallida, Melipona fasciata, and a necrophage of the genus Trigona demonstrate that Bacillus species are common associates of Apoidea and could participate both in metabolic conversion of food and in the control of competing and/or spoilage microorganisms