Competitive interactions in insect parasitoids: effects of microbial symbionts across tritrophic levels

Competition for hosts is a common ecological interaction in insect parasitoids. In the recent years, it has become increasingly evident that microorganisms can act as 'hidden players' in parasitoid ecology. In this review, we propose that parasitoid competition should take into consideration the microbial influence. In particular, we take a tritrophic perspective and discuss how parasitoid competition can be modulated by microorganisms associated with the parasitoids, their herbivore hosts, or the plants attacked by the herbivores. Although research is still in its infancy, recent studies have shown that microbial symbionts can modulate the contest outcome. The emerging pattern is that microorganisms not only affect the competitive traits of parasitoids but also the fighting arena (i.e. the herbivore host and its food plant), in which competition takes place. We have also identified important gaps in the literature that should be addressed in future studies to advance our understanding about parasitoid competition.

Automated summary

Competition for hosts is common in insect parasitoids, and it is increasingly recognized that microorganisms play a significant role in parasitoid ecology. This review emphasizes the importance of considering microbial influence in parasitoid competition, particularly from a tritrophic perspective. Recent studies have shown that microbial symbionts not only affect the competitive traits of parasitoids but also the environment in which competition takes place. However, there are still important gaps in the literature that need to be addressed to advance our understanding.