Polybia wasp biting interactions recruit foragers following experimental worker removals

Communicative interactions between colony members, or worker connectivity, can affect division of labour in insect societies. Nestmate workers of the eusocial paper wasp Polybia occidentalis engage in biting interactions, and correlational evidence suggests that biting promotes foraging by the workers that are bitten. I used experimental forager removals to test whether biting is a form of worker connectivity, inducing new recruits to enter the foraging force. I observed colonies with marked workers during a pretreatment (control) period, then removed all arriving foragers on the following day. Foraging ceased after several hours of forager removals, and remained depressed on the following morning. I grouped the remaining workers into four behavioural categories: nonforagers, individuals that stopped foraging after the manipulation, continuing foragers that were active before and after the manipulation and recruited foragers that began foraging after the manipulation. After the manipulation, the recruited foragers were bitten at similar rates to the continuing foragers and, most importantly, were the only ones that were bitten at significantly increased rates after the manipulation. Most recruits were observed being bitten before they began foraging. However, some recruits were not observed being bitten, and worker responses to biting were often gradual. These patterns suggest that the effect of biting is to modulate the probability of foraging in bitten workers. The experiments show that biting helps to induce foraging. Biting is a form of worker connectivity, serving as a mechanism of communication between Polybia workers that affects colony responses to changing conditions.