RESTRICTED INGESTION OF BACTERIA BY FIRE ANTS

Fire ant queens and workers from colonies fed to repletion on Serratia marcescens, Bacillus thuringiensis, or Bacillus sphaericus were asept ically dissected, and homogenates of their thoracic and gastric guts w ere plated on appropriate media to determine whether bacteria were ing ested. All three species of bacteria were effectively excluded from th e gut of both queens and workers. A small, slow-growing, Gramnegative bacterium, noted in some of the test queens, was subsequently isolated from the gut of 8 (13.8%) of 58 queens from field colonies. This bact erium was partially characterized, but was not identified. Implication s for microbial formicide research are discussed. (C) 1996 Academic Pr ess. Inc.