However, issues regarding their evolutionary consequences and fitness costs have long been debated 12, 15, 16, 17. two or more eggs being laid into a single host by one or more parasitoid females, and superparasitism avoidance are among the most fundamental intraspecific competition behaviours of solitary wasps 12, 13, 14.
Furthermore, the offspring of parasitic wasps are typically confined to the host that was parasitized, so the strategies of the ovipositing female therefore largely determine her reproductive outputs her strategy is therefore under strong natural selection. Intraspecific competition is widespread and particularly important in communities of parasitoid wasps and other parasites, whose development closely relies on the condition of hosts 10. On the other hand, competition induces natural selection that might enable rapid adaptation to novel conditions and niche expansion for the populations at longer timescales 5, 8, 9. Under limited resources, intraspecific competition limits the increase in population size and potentially lowers genetic diversity due to genetic drift hence, the population is more likely to become extinct when exposed to new environments 4, 6, 7. How competition shapes the communities of animals and plants has been one of the central topics in ecology and evolution for decades 1, 2, 3, 4, 5. Our study suggests that superparasitism avoidance is adaptive for a parasite and adds to our understanding of how the molecular manipulation of host behaviour has evolved in this system. We further uncover an evolutionary scenario in which neofunctionalization and specialization gave rise to the novel role of RhoGAP domain in avoiding superparasitism, with an ancestral origin prior to the divergence between Leptopilina specialist and generalist species. We combine multi-omics and in vivo functional studies to characterize a small set of RhoGAP domain-containing genes that mediate the parasite’s manipulation of host escape behaviour by inducing reactive oxygen species in the host central nervous system. Here, we apply the Drosophila parasite Leptopilina boulardi as a study system and find that this solitary endoparasitic wasp provokes a host escape response for superparasitism avoidance.
However, the underlying mechanisms and ecological contexts of these phenomena remain underexplored. Among the evolutionary arms races between parasites, one of the most fundamental and intriguing behavioural adaptations and counter-adaptations are superparasitism and superparasitism avoidance. Intraspecific competition is a major force in mediating population dynamics, fuelling adaptation, and potentially leading to evolutionary diversification.