Biology and host specificity of an Asian box tree moth parasitoid, candidate for classical biological control in Europe and North America

The box tree moth (Cydalima perspectalis) is invasive in Europe and North America, where it lacks natural enemies. Eriborus sp., native to Asia, appears as a promising biocontrol agent of the box tree moth. To determine whether the parasitoid is suitable for use as a classical biological control agent against C. perspectalis, we studied the preoviposition period, host instar suitability, and host specificity of Eriborus sp. The parasitoid was able to parasitize box tree moth larvae within 24 hours of emergence, with an increased probability of attack from 33% on the first two days to 80% four days after its emergence. Eriborus sp. oviposited successfully in all instars of C. perspectalis larvae, with significant differences in parasitisation depending on the larval instar – the highest parasitism was found for third and fourth instar larvae. Eriborus sp. development time decreased with increasing host instars. Eriborus sp. selectively attacked the non-target crambid species O. nubilalis, with lower attack rates on O.nubilalis, but no attack incidence in the case of S. frugiperda and M. brassicae. These results highlight the specificity of Eriborus sp. on the box tree moth at least under laboratory conditions with no choice tests. Biocontrol, Cydalima perspectalis, Eriborus sp., Invasive, Parasitoid, Specificity

The box tree moth (Cydalima perspectalis) is invasive in Europe and North America, where it lacks natural enemies. Eriborus sp., native to Asia, appears as a promising biocontrol agent of the box tree moth. To determine whether the parasitoid is suitable for use as a classical biological control agent against C. perspectalis, we studied the preoviposition period, host instar suitability, and host specificity of Eriborus sp. The parasitoid was able to parasitize box tree moth larvae within 24 hours of emergence, with an increased probability of attack from 33% on the first two days to 80% four days after its emergence. Eriborus sp. oviposited successfully in all instars of C. perspectalis larvae, with significant differences in parasitisation depending on the larval instar – the highest parasitism was found for third and fourth instar larvae. Eriborus sp. development time decreased with increasing host instars. Eriborus sp. selectively attacked the non-target crambid species O. nubilalis, with lower attack rates on O.nubilalis, but no attack incidence in the case of S. frugiperda and M. brassicae. These results highlight the specificity of Eriborus sp. on the box tree moth at least under laboratory conditions with no choice tests. Key words: Biocontrol, Cydalima perspectalis, Eriborus sp., Invasive, Parasitoid, Specificity