Parasitism activity of Diachasmimorpha longicaudata (Ashmead) (Hymenoptera: Braconidae) and Aganaspis daci (Weld) (Hymenoptera: Figitidae) against Ceratitis capitata (Wiedemann) (Diptera: Tephritidae) under Mediterranean climatic conditions

Abstract

Background: Ceratitis capitata (Wied.), the Mediterranean fruit fly, is one of the key pest species affecting citrus production around the Mediterranean coasts of Spain, Morocco and Tunisia. During the past decade the IVIA (Valencian Institute for Agricultural Research) has imported several parasitoid species to enhance a Biological Control (BC) program against this pest. Soon after the introduction of Diachasmimorpha longicaudata (Ashmead) in 2009, a native parasitoid, the figitid Aganaspis daci (Weld), was identified in Bétera, a town in the province of Valencia. This work will contribute to highlight the importance of the two species within the BC program against C. capitata in the study areas. Methods: To determine the influence of climatic factors on parasitism rate and Medfly mortality, apples artificially infested with Medfly larvae were individually exposed to five parasitoid couples for one week under natural conditions. Forty wood-framed mesh cages (twenty for each parasitism rate and immature development) of each parasitoid species were tested weekly over 10 weeks across one year. Results: Under Mediterranean climatic conditions, D. longicaudata exerted a high parasitism rate compared with A. daci. Extreme winter and summer temperatures seem to affect the immature development of both species. A higher immature mortality was observed for A. daci throughout the year, compared with D. longicaudata. Adult parasitoid species were capable of parasitizing C. capitata L2/L3 larvae at the extreme temperatures tested. Conclusions: This study suggests that A. daci shows a good performance as well as D. longicaudata against C. capitata under Mediterranean climatic conditions. Further studies are required to determine the influence of other climatic factors and whether the two parasitoid species act in synergism.