Performance ofSclerodermus brevicornis,a parasitoid of invasive longhorn beetles, when reared on rice moth larvae

摘要

Biological control efficiency can be improved by developing effective mass-rearing systems to produce large numbers of high-quality parasitoids. This study explored an alternative host for rearingSclerodermus brevicornis(Kieffer) (Hymenoptera: Bethylidae), a potential biocontrol agent for the suppression of exotic and invasive wood-boring longhorn beetle (Coleoptera: Cerambycidae) populations in the European agroforestry ecosystems. We tested larvae of the rice moth,Corcyra cephalonicaStainton (Lepidoptera: Pyralidae), as host for the parasitoid. We quantified the probability and timing of host attack and parasitism as well as reproductive success, offspring production, and the characteristics of adult offspring. AsS. brevicornisis a quasi-social species (multiple females, communally produced offspring broods), we also explored the effects of varying the number of females to which individual hosts were presented, with the aim of determining the optimal female-to-host ratio. As time to host attack can be a limiting factor inS. brevicornisrearing protocols, we tested the use of adult females of another bethylid species,Goniozus legneriGordh, to paralyseC. cephalonicalarvae prior to presentation. We identified the conditions within our experiment that maximized offspring production per host and offspring production per adult female parasitoid. We found thatC. cephalonicais suitable as a factitious host and, as it is considerably more straightforward for laboratory rearing than cerambycid species, it is a good candidate for adoption by futureS. brevicornismass-rearing and release programmes.