Interspecific interaction between Telenomus remus (Hymenoptera: Platygastridae) and Trichogramma pretiosum (Hymenoptera: Trichogrammatidae) on Spodoptera frugiperda (Lepidoptera: Noctuidae) eggs

Tatiana R Carneiro,Odair A Fernandes

doi:10.1590/s0001-37652012000400027

Abstract

This work aims to evaluate the interspecific interaction between Trichogramma pretiosum and Telenomus remus, two biological control agents of fall armyworm (Spodoptera frugiperda) eggs. Eggs of Spodoptera frugiperda previously parasitized by Telenomus remus were offered to Trichogramma pretiosum, and those parasitized by Trichogramma pretiosum were offered to Telenomus remus. The previously parasitized eggs were tested at different embryonic development stages for each parasitoid. In addition, to evaluate the competition between species, Spodoptera frugiperda eggs were offered to the parasitoids simultaneously. The behavior of the insects was recorded under a stereomicroscope. When Spodoptera frugiperda eggs were previously exposed to either parasitoid, there was no emergence of the other parasitoid. When the Telenomus remus and Trichogramma pretiosum females were placed together with Spodoptera frugiperda eggs, Telenomus remus had a greater parasitism rate. Except searching time, all Trichogramma pretiosum behaviors took a longer time than Telenomus remus behaviors. Thus, despite belonging to different families, each of these parasitoids is able to recognize host eggs previously parasitized by the other. So, this suggests that the recognition mechanism involved is not exclusively specific.

Highlights

Interspecific or intraguild competition can be defined as the interaction between two species for the same food resource and/or for the same host (Rosenheim et al 1995)
Prior to an introduction or release of natural enemies, such interactions should be well characterized and carefully studied, since various aspects may interfere with the action of biological control agents (Kester and Jackson 1996, Vilela and Pallini 2002, Babendreier et al 2003, Arim and Jaksic 2005)
If a generalist predator and/or parasitoid develop a preference for another natural enemy, this can cause the insect pest population to increase (Venzon et al 2001) and impact the whole integrated pest management program

Summary

Introduction

Interspecific or intraguild competition can be defined as the interaction between two species for the same food resource and/or for the same host (Rosenheim et al 1995). It can occur at different trophic levels and has the potential to affect distribution, abundance and evolution of each species involved (Odum 1988, Polis et al 1989, Arim and Marquet 2004). Prior to an introduction or release of natural enemies, such interactions should be well characterized and carefully studied, since various aspects may interfere with the action of biological control agents (Kester and Jackson 1996, Vilela and Pallini 2002, Babendreier et al 2003, Arim and Jaksic 2005). If a generalist predator and/or parasitoid develop a preference for another natural enemy, this can cause the insect pest population to increase (Venzon et al 2001) and impact the whole integrated pest management program

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