Functional and Numerical response and Mutual interference of Goniozus legneri (Hymenoptera: Bethylidae) against Cydia pomonella (Lepidoptera: Tortricidae): its implications for Biological Control

Abstract

The functional and numerical response and the mutual interference are key components in the selection of parasitoids for biological control. In this study, functional and numerical responses and mutual interference of Goniozus legneri to different densities of fifth instar Cydia pomonella larvae were studied under laboratory conditions. Logistic regression was used to determine a type II functional response. The attack rate, handling time, the parasitoid searching efficiency and the maximum mortality rate were estimated by fitting the Holling model to the data. The numerical response of the parasitoid did not vary based on the availability of codling moth larvae. The negative value of the interference coefficient (–0.228) in the mutual interference analysis showed an inverse relationship between parasitoid density and per capita searching efficiency. It is concluded that a ratio of parasitoid density equal to C. pomonella density is the most effective ratio when programming release trials. The findings of this study contribute significantly to increasing the knowledge of G. legneri and its potential as a biocontrol agent.