Insights into the functional response of Neotropical-native parasitoids for enhancing their large-scale production on Anastrepha fraterculus

Abstract

Anastrepha fraterculus, or South American Fruit Fly, is one of South American countries' most damaging insect pests to fruit production and trade. This Neotropical-native dipteran species also has quarantine value for those world regions unaffected by this pest. Using indigenous parasitoids instead of exotic species is a potential control tool within A. fraterculus integrated management programs (IMP). Augmentative biological control (ABC) is an eco-friendly strategy that should be implemented. This approach is based on large-scale parasitoid rearing for mass release in a target area. The successful rearing of indigenous parasitoids requires understanding host-parasitoid interaction under laboratory conditions. That is because parasitoid foraging and reproduction are closely linked to their host. Thus, functional response analysis can assess the change in the consumption rate of a given host by a given parasitoid based on the time spent by the consumer searching for and manipulating the resource. In this study, the package "frair" from R software was used for functional response estimation, enabling selection, fitting, and comparison among standard response models recorded from four Neotropical-native parasitoid species naturally associated with A. fraterculus, such as the pupal parasitoid Coptera haywardi, and larval parasitoids Ganaspis pelleranoi, Doryctobracon crawfordi and Opius bellus Gahan. Results showed that C. haywardi and G. pelleranoi were highly efficient at host utilization in terms of attack rate and discarded hosts. Furthermore, G. pelleranoi showed even more interesting traits, like shorter host manipulation time and a type III functional response, contributing to host/parasitoid system stability. Therefore, both parasitoids are recommended for rearing and use in ABC.