Behavior and Chemical Ecology of Diachasmimorpha longicaudata: basic studies as tools to improve biological control programs against fruit fly in Argentina

DIEGO F. SEGURA; FRANCISCO DEVESCOVI ; CLAUDIA C. CONTE; JUAN P. WULFF; SERGIO M. OVRUSKI; MARIANA M. VISCARRET; SILVIA B. LANZAVECCHIA; JORGE L. CLADERA

Congreso; SICONBIOL 2019; 2019

Tephritidae fruit flies (Diptera) are amongst the most destructive pest of commercial fruit worldwide. Environmentally friendly control strategies used against such pests include a biological control component, mainly through the use of exotic parasitoids. In particular, the wasp Diachasmimorpha longicaudata Ashmead (Braconidae) is one of the most commonly used biocontrol agents. This larval-pupal parasitoid is native to the Indo-Pacific region and was first imported to the Americas in the 1970s to control native fruit flies of the genera Anastrepha and the highly destructive Mediterranean fruit fly, Ceratitis capitata Wied. Since then, this parasitoid has been introduced in several countries, including Brazil and Argentina. In this presentation, we will summarize a series of studies focused on the foraging behavior of D. longicaudata females, particularly centered in the host searching behavior. We found that parasitoid females are able to detect fruit infested with larvae using chemical cues, derived from the host larvae, as well as from the substrate (rotten fruit). GC-MS analyses of the volatile compounds released by these attractive sources allowed to postulate specific compounds that females would use to locate host larvae. Our work has shown that females have innate preference for specific host fruit odors and the basis of this preference seems to be related more to the easiness of attacking host larvae buried into the fruit flesh than to the quality of the host larvae. Color, on the other hand, did not trigger an innate preference in this species. However, we found that D. longicaudata has high ability to associate visual, as well as chemical, cues during host searching, making them more and more efficient at host finding with experience. The potential contribution of studies such as those carried out by our group to the management of insect pests through natural enemies will be further discussed.