Yeasts associated with the infrabuccal pocket and colonies of the carpenter ant Camponotus vicinus

After scanning electron microscopy indicated that. the infrabuccal pockets of carpenter ants (Camponolus vicinus) contained numerous yeast-like cells, yeast associations were examined in six colonies of carpenter ants from two locations in Benton County, in western Oregon. Samples from the infrabuccal-pocket contents and worker ant exoskeletons, interior galleries of each colony, and detritris and soil around the colonies were plated on yeast-extract/malt-extract agar augmented with 1 M hydrochloric acid and incubated at 25 C. Yeasts were identified on the basis of morphological characteristics and physiological attributes with the BIOLOG(R) microbial identification system. Yeast populations from carpenter ant nest material and material surrounding the nest differed from those obtained from the infrabuccal pocket. Debaryomyces polymorphus was isolated more often from the infrabuccal pocket than from other material. This species has also been isolated from other ant species, but its role in colony nutrition is unknown.