Lobesia botrana as a preferred host of Campoplex capitator, the most occurring larval parasitoid in European vineyards

Parasitoids are major biological agents in crop protection, and understanding their preference towards specific host species is a key aspect of successful pest control. In the present study, we have examined the host preferences of the larval parasitoid Campoplex capitator (Hymenoptera: Ichneumonidae), one of the major natural enemies for tortricid grapevine pest populations in European vineyards. Using a test choice between its two main and sympatric hosts, we wanted to determine whether C. capitator females that emerged from Lobesia botrana (Lepidoptera: Tortricidae) also prefer its natal host L. botrana, or Eupoecilia ambiguella (Lepidoptera: Tortricidae) as host; and consequently, if it could be a good candidate as a bio-agent for these species. Our results distinctly showed that naive C. capitator females preferred L. botrana over E. ambiguella as host, as they directly sought out new L. botrana hosts. Overall, it reveals that C. capitator could be a very efficient parasitoid to control L. botrana populations. Our results might also suggest the importance of natal host in parasitoid host preference, which should be considered in the future when mass-rearing bio-agents.