Asymmetries affecting aggressive contests between solitary parasitoids: the effect of host species. (16th October 2020)

• Record Type: Journal Article
• Authors: Guerra-Grenier, Eric; Abram, Paul K; Brodeur, Jacques
• Editors: Herberstein, Marie
• Is Part Of: Behavioral ecology. Volume 31:Number 6(2020)
• Page Start: 1391
• Page End: 1400
• Publication Date: 2020-10-16
• Subjects: animal competition -- bourgeois rule -- developmental plasticity -- Pentatomidae -- resource-holding potential -- Telenomus podisi; Animal behavior -- Periodicals; Behavior evolution -- Periodicals; Ecology -- Periodicals; Psychology, Comparative -- Periodicals; 591.5
• DOI: 10.1093/beheco/araa096
• Languages: English
• ISSNs: 1045-2249

Abstract

Abstract: Conflicts in animals are usually resolved based on asymmetries, where contest winners are often those that value a resource the most and/or those who have the greatest potential to retain it. In parasitoid wasps, contests between females determine which individual exploits hosts for offspring production. Previous studies on solitary parasitoids rarely considered the role of biotic factors generating phenotypic variation that could influence the strength of asymmetries. Some parasitoid species parasitize host species of various sizes, producing offspring that vary considerably in size and potentially fighting ability. In this study, we reared the egg endoparasitoid Telenomus podisi (Hymenoptera: Scelionidae) on two host species to measure the effect of body size on contest resolution and how it interacts with ownership and resource value (RV) asymmetries. Our results showed that ownership status best predicts the final contest outcome when similar-sized wasps fight over hosts. The frequency and outcomes of individual fights structuring contests were better explained by the difference in the number of eggs laid in the hosts by each female at a given time. When contestants varied in body size, larger intruders frequently dislodged small owners regardless of ownership and RV asymmetries. These results imply that body size is an important factor to consider in solitary parasitoid contests and that it can overshadow the effects of other asymmetries. Our study suggests that host community diversity could have a direct effect on parasitoid contests and that biotic communities, through their effects on animal phenotypes, may play an underrated role in contest resolution. Abstract : When animals compete over a resource, the winner of the contest is usually the one that values it the most or that is the best at fighting for it. In insect parasitoids, fights among females determine who gets to produce offspring. Here, we show that the size of the natal host has a direct effect on the fighting ability of contestants, suggesting that host biodiversity is linked to parasitoid conflict resolution.