Submitted to: Journal of Invertebrate Pathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/29/1996
Publication Date: N/A
Interpretive Summary: Efforts are being made to find microbes with properties suitable for use in the control of fire ants. These ants ingest only liquid food, filtering out small particles. This work tests whether fire ant queens and workers ingest bacteria. The tests reported here reveal that three species of bacteria upon which they fed failed to enter the gut of the ants. Though the worker ants might carry the bacterium back to the nest, queens are not likely to become infected. Any one intending to look for microbes with activity against fire ants must be cognizant of how a fire ants feed and how the colony is nourished. Knowing this in advance, companies and researchers looking for ant biological control agents will be better able to design and conduct a screening program for biological agents to control fire ants.
Technical Abstract: Fire ant queens and workers from colonies fed to repletion on Serratia marcescens, Bacillus thuringiensis, or Bacillus sphaericus, were aseptically dissected, and homogenates of their thoracic and gastric guts were plated on appropriate media to determine whether bacteria were ingested. All three species of bacteria were effectively excluded from the gut of both queens and workers. A small, slow growing, Gram negative bacterium, noted in some of the test queens, was subsequently isolated from the gut of eight (13.8%) of 58 queens from field colonies. This bacterium was partially characterized, but was not identified. Implications for microbial formicide research are discussed.