THE INFRABUCCAL CHAMBER OF CAMPONOTUS MODOC (HYMENOPTERA: FORMICIDAE): INGESTION, DIGESTION, AND SURVEY OF BACTERIA

Abstract:
Carpenter ants feed on both liquid and solid food. Baiting for carpenter ants has proceeded using both of these media to introduce toxicants into the colony for control. Ingestion of food particles larger than 100 microns is effectively curtailed by the specializations of the epipharynx, hypopharynx, and various maxillary and labial structures. These filtration mechanisms function as food enters or exits the infrabuccal chamber (pocket), an oral storage area. Solid food materials are taken into the infrabuccal chamber of Camponotus modoc Wheeler workers where secretions from head and thoracic glands aid in digestion. A liquid diet can then pass through the filtering mechanism as it exits the infrabuccal chamber into the pharynx. It was hypothesized that the infrabuccal chamber contained bacteria that may also be a factor in digestion and ultimately in the dissemination of toxicants in baits. Using sterile technique, infrabuccal chambers were removed via microdissection from the heads of ants. The contents were cultured on Muller Hinton, R 2-A, and chitin agar. Plates were incubated at room temperature under aerobic, microaerophilic, and anaerobic conditions. The mixed microbial flora were predominately Gram positive rods in the genus Bacillus. Gram positive cocci, Gram negative rods, and yeasts were also found.