Is Fopius arisanus (Hymenoptera: Braconidae) a suitable biological control agent of Bactrocera dorsalis (Diptera: Tephritidae) in multi-crop orchards?

In the present study, we investigated the bottom-up effects of four economically important host fruit species (guava, mandarin orange, plum, pear) on Bactrocera dorsalis parasitoid Fopius arisanus in terms of emergence, parasitism, sex ratio, developmental duration, longevity and body size. Our results showed that F. arisanus reared on guava infested with B. dorsalis had highest emergence, parasitism, sex ratio and longevity, while these parameters were lower on B. dorsalis-infested mandarin orange. Moreover, body size of F. arisanus (wing, hind tibia and body lengths for both sexes and ovipositor length for female) varied significantly among the B. dorsalis-infested fruits, with mandarin orange providing the biggest emergent body size for both sexes and guava providing the smallest. The shortest preimaginal developmental time for both sexes was in infested plums and the longest in infested mandarin orange. Therefore, we inferred that B. dorsalis-infested guava is the most suitable host–host plant combination for F. arisanus fitness among the tested fruit-host combinations. Our findings corroborates that the ability of some tested fruit species to serve for the permanent establishment of F. arisanus in the field, which will aid in boosting the efficiency of F. arisanus as a biological control agent, especially in multi-crop orchards.