Flexible foraging decisions made by workers of the social wasp Vespula germanica (Hymenoptera: Vespidae) in response to different resources: influence of ontogenetic shifts and colony feedback

MATTIACCI, ANALÍA; MASCIOCCHI, MAITÉ; CORLEY, JUAN C.

INSECT SCIENCE

WILEY-BLACKWELL PUBLISHING, INC

Año: 2021 p. 1 - 14

1672-9609

Decisions made by foraging animals conform a complex process based onthe integration of information from multiple external environmental stimuli and internalphysiological signals, which in turn are modulated by individual experience and a detec-tion threshold of each individual. For social insects in which foraging is limited to givenage subcastes, individual foraging decisions may also be affected by ontogenetic shiftsand colony requirements. We studied the short-term changes in foraging preferences ofthe generalist wasp Vespula germanica, focusing on whether the individual response todifferent resources could be influenced by the ontogenetic shifts and/or by social interac-tion with nestmates. We carried both laboratory and field experiments to confront workerwasps to a short-term resource switch between either protein or carbohydrate-based foods.We tested the response of (1) Preforager workers (no foraging experience nor interactionwith other wasps), (2) Forager workers (experience in foraging and no colony feedback),and (3) Wild forager workers (foraging naturally and exposed to free interactions withnestmates). We evaluated the maxilla-labium extension response (MaLER) for laboratoryassays or the landing response for field assays. We observed that for wasps deprived ofcolony feedback (either preforagers or foragers), the protein-rich foods acceptance thresh-old increased (and thus a lower level of foraging on that item was observed) if they hadforaged on carbohydrates previously, whereas carbohydrates were accepted in all assays.However, wasps immersed in a natural foraging context did accept protein foods regardlessof their first foraging experience and reduced the carbohydrates collected when trained onprotein foods. We provide evidence that short-term changes in foraging preferences de-pend on the type of resource foraged and on the social interactions, but not on ontogeneticshifts.