Functional and numerical response and mutual interference of Goniozus legneri (Hymenoptera: Bethylidae) on Cydia pomonella (Lepidoptera: Tortricidae): Its implications for biological control

The functional and numerical response and the potential for mutual interference are key components in the selection of parasitoids for biological control. In this study, functional and numerical responses of Goniozus legneri to different densities of fifth instar Cydia pomonella larvae and mutual interference of this parasitoid were studied under laboratory conditions. Logistic regression was used to find the type of functional response and the result was type II. The attack rate, handling time, the parasitoid searching efficiency and the maximum host 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. This suggests that when the density of G. legneri and C. pomonella larvae is equivalent, the parasitoid proves to be more effective in pest control. The findings of this study contribute to increasing the knowledge of G. legneri and its potential as a biocontrol agent.