SUMMARY

The guts of 388 adult worker honey bees. Apis mellifera. from caged control colonies, from colonies fed (2.4-dichlorophenoxy) acetic acid (2.4-D). and from colonies fed a combination ofoxytetracycline and fumagillin were examined over a period of 13 months for organisms of the genus Bacillus. One hundred and ten organisms belonging to 13 species were identified. Bacillus megateriwn. B. subtilis. and B. pu-mtlus were the most frequently isolated organisms and were found in bees in all three treatment groups. The antibiotics and 2.4-D reduced the number of bee guts containing Bacillus. No Bacillus or ganisms were isolated during the hot summer months of June-September. Thus, weather may also in fluence the composition of the gut microflora