Temporal and spatial components of the yeast flora of the red imported fire ant (hymenoptera: formicidae)

Few investigations have examined the relationship between Solenopsis complex and its internal microflora. Most investigations on the red imported fire ant are either control oriented or emphasize the species' negative impact on ecosystems. Therefore, the objective of this research were (1) to isolate and identify yeasts from the red imported fire ant (Solenopsis invicta (2) to determine the impact of associated yeasts on red imported fire ant colony vigor, and (3) to clarify the significance of the association by obtaining and comparing sterol profiles of the yeast flora and the red imported fire ant.

Colonies were collected from five locations in Texas: Beaumont, Huntsvllle, Waco, Stephenville, and Abilene. These sites represent a transect along a decreasing moisture gradient from the southeastern to the northwestern region of the state. Colonies were randomly collected during the winter of 1992, and the spring, summer, and fall months of 1993. Physiological and morphological tests showed that the 327 yeast isolates from Solenopsis invicta haemolymph represent five yeast species: Candida parapsilosis (168 Isolates), Candida lipolytica (123 isolates), Candida guillermondii (18 isolates), Candida rugosa (9 Isolates), and Debaryomyces var hansenii (9).