Resource limitation, intragroup aggression, and brain neuropeptide expression in a social wasp
Walton, Alexander; Toth, Amy (2021), Resource limitation, intragroup aggression, and brain neuropeptide expression in a social wasp, Dryad, Dataset, https://doi.org/10.5061/dryad.gqnk98sng
1. Nourishment can have profound effects on social behavior, including aggressive interactions between individuals. However, how nutritional resource availability and limitation affects intraspecific aggression remains somewhat contested. The prevailing theoretical and empirical understanding is that when nutritional resources are limited, inter-individual competition and aggression will increase. However, findings from several social animals suggest that limited nutrition can lead to increased cooperation, including by a reduction in inter-individual aggression.
2. We suggest that in social insect colonies, where nourishment is often important in determining differences between the reproductive and non-reproductive worker behavioral castes, the link between an individual’s nourishment and their future reproductive potential may be a key missing element of models that predict how nutritional resource availability affects inter-individual aggression.
3. We investigated how nourishment influenced intra-colony aggression and its molecular correlates in colonies of the social paper wasp Polistes fuscatus, which workers that maintain flexible reproductive potential as adults. We subjected colonies to either a high or low feeding treatment, and examined subsequent effects on behavior, physiology, and brain gene expression.
4. We found that nutritional restriction reduced aggressive interactions, suggesting increased social cohesion when resources are limiting. Thus, individual worker paper wasps appear to have the capacity to adjust their behavior (e.g., reduced aggression) in response to nutritional stress, investing nutritional resources in the colony when resources are limiting, and in the self when resources are abundant.
5. Differential brain gene expression results implicate two well-known neuropeptides associated with aggression and/or nutrient signaling across taxa, Tachykinin and Neuropeptide-F, as possible mediators of nutritionally-dependent intra-colony aggression. This adds to a growing understanding that deeply conserved genes associated with core, conserved behaviors such as feeding and aggression in solitary insects can play a role in the regulation of social plasticity in more highly social species.
National Science Foundation, Award: 1701887