Biology and demographic parameters of the ectoparasitoid Goniozus legneri (Hymenoptera: Bethylidae) reared on Lobesia botrana (Lepidoptera: Tortricidae)

Abstract

The European grapevine moth (EGVM)Lobesia botrana is currently harming Argentine viticulture,a key agri-industrial activity in this country.The combined use of insecticides and mating disruptiontechniques is providing adequate pest control.Still, other tactics are worth investigating to reducecrop protection costs and improve environmentallysafe management of this key pest. As for biologicalcontrol, the native gregarious ectoparasitoid Goniozuslegneri has shown efficiency in reducing populationsof various lepidopteran pests with concealed feedinghabits. In this paper, we report studies on biologicaltraits of G. legneri reared on EGVM to determineits reproductive performance on the pest. Through alife table approach, we compared G. legneri populationparameters under two rearing conditions: 1) byreplacing host larvae after each oviposition event, i.e.,continuous oviposition (CO), or 2) by allowing parentalcare (PC) for four days, a typical behavior in thisspecies. Goniozus legneri egg-to-adult developmenttime was 14.9 (± 2.6) days and it exhibited a low survivalrate (25.2%) under the two rearing conditions.The clutch size ranged from 3.76 to 7.30 eggs perhost larvae, under CO or PC conditions, respectively.Intrinsic rates of increase (rm) estimated in CO andPC tests were low but positive, which indicates thatG. legneri can develop on EGVM. The study providesbasic knowledge to use G. legneri as a biological controlagent of EGVM through augmentative and conservationbiological control approaches.