Response of the braconid parasitoid Diachasmimorpha longicaudata (Ashmead) to fruits infested by oriental fruit fly, Bactrocera dorsalis (Hendel)

Abstract

Biological control is an increasingly employed method in the management of tephritid pests because it is ecologically benign and target specific. The parasitoid Diachasmimorpha longicaudata (Ashmead) (Hymenoptera: Braconidae) is considered an effective biological control agent of tephritid pests, but there are few studies on its behavioral responses to the local host types. This information is necessary for the success of the post-release establishment of the parasitoid. The parasitoid’s behavior on oriental fruit fly Bactrocera dorsalis (Hendel) (Diptera: Tephritidae) infested (1 and 4d old) and uninfested fruits were assessed to understand the efficacy and preference of D. longicaudata for different host fruits. The guava was considered reference fruit to compare with banana, carambola and apple. In olfactory bioassays, the parasitoid preferred banana and guava over apple and carambola, and guava that had been infested for a longer period of time. In no-choice and dual-choice bioassays, the parasitism rate, sex ratio, and fertility were compared and in dual-choice bioassays, the parasitoid exhibited significant differences of the above parameters in guava-banana and guava-carambola but not in the guava-apple trial. In the no-choice bioassays, nothing differs substantially between guava and other fruits except the parasitism rate of guava and banana which was significantly greater in guava. This study will help to understand the post-release behavior of the parasitoid to implement the integrated pest management programs of the oriental fruit fly.