Isolation increases the performance of social behaviors when ants are reunited with nestmates. Octopamine (OA) mediates isolation induced social behaviors in ants. To study the behavioral mechanism of OA on social behavior, we conducted two sets of experiments. First, we acutely treated adult Pheidole dentata workers with OA following 5-day isolation, and recorded their social interactions. In the second experiment, the same behavioral process was employed but ants were treated during the pupal stage and tested as adults to evaluate the developmental effects of OA. Based on prior research we expected decreased social behaviors following OA treatment in adults, and increased social behaviors in adults developmentally treated with OA. Contrary to our expectations, we found an increase in the duration of social behaviors in OA treated adults, and no effect of OA on the duration of social behaviors compared to controls in the developmental group. However, vehicle treatment during development significantly reduced social behaviors as adults, suggesting a protective role of OA that rescued behaviors back to control levels. Therefore acute OA treatment differentially affects social behaviors in normal and developmentally treated adult ants
