The semiochemistry of fruits as seen through the lens of Tephritid fruit flies and their parasitoids

Abstract

The tephritid fruit fly is a term well-known in fruit and vegetable production. Several techniques including the use of parasitoids have been deployed for fruit fly control. In Sub-Saharan Africa,Fopius arisanus (Sonan) and Diachasmimorpha longicaudata (Ashmead) (Hymenoptera:Braconidae) have been introduced to supplement the existing native parasitoids. Although the effectiveness of parasitoids is known, there is a knowledge gap in the semiochemical-mediated interactions among tree-attached fruits, fruit flies, and parasitoids. Here, I aimed to compare the attraction of fruit flies and parasitoids to different fruits, evaluate fruit fly performances, in terms of recovered puparia, in these fruits and elucidate the fruits’ headspace volatile compounds.First, the attraction of Bactrocera dorsalis (Hendel), F. arisanus and D. longicaudata to the headspace volatiles of different treatments of three varieties of mangoes were compared. B.dorsalis and the two parasitoids were differentially attracted to the mango headspace volatiles compared to the control, clean air. A higher number of B. dorsalis puparia was recovered in the Apple mango variety (81.7%) but none from the Kent variety. Gas chromatography-mass spectrometry revealed several organic compounds with qualitative and quantitative differences.The majority of tentatively identified compounds were esters (33.8%). Most compounds were produced at higher concentrations by fruit fly-infested mangoes than non-infested ones