Meeting Abstract
77.2 Wednesday, Jan. 6 Harvester Ant Foraging Decisions are Informed by Cues Present in Cuticular Hydrocarbons Detected During Social Interactions GREENE, MJ; Univ. of Colorado Denver michael.greene@ucdenver.edu
The regulation of worker activity by social insect colonies is performed in a non-hierarchical manner. No one entity, including the queen, has the ability to control the precise activity of the other colony members. Instead, workers make individual behavioral decisions informed by the assessment of local cues. Colony-wide changes in behavior reflect the many individual behavioral decisions of the workers. Social interactions can provide important local cues. In harvester ants (Pogonomyrmex barbatus ), foraging is stimulated by the return of a different task, patrollers, to the nest. Colonies are responsive to the rate of patroller return and when patrollers are prevented from returning to nest, foraging will not begin by the colony that morning. Foragers recognize patrollers returning to the nest using cues present in patroller cuticular hydrocarbons. Cuticular hydrocarbons are a mixture of long-chain n-alkanes, methyl-branched alkanes, and n-alkenes which serve in communication, prevention of abrasion to the cuticle, and prevention of water loss. Harvester ant workers that work outside the nest, such as patrollers and foragers, have a higher amount of n-alkanes as compared workers that spend short amounts of time outside of the nest, such as nest maintenance workers. In this study, I tested the hypothesis that high relative abundance of n-alkanes in cuticular hydrocarbons acts as a cue that allows foragers to identify patrollers during social interactions important in the regulation of colony foraging. I removed patrollers to prevent foraging and returned ant mimics to the nest, small glass beads coated with hydrocarbons, and then measured foraging levels. My data supported the hypothesis; when nest maintenance workers were supplemented with n-alkanes hydrocarbons, colonies responded with foraging in a similar fashion as the return of patroller hydrocarbons.
