Side Effects of Pesticides on the Olive Fruit Fly Parasitoid Psyttalia concolor (Szepligeti): A Review

Pesticide applications in olive orchards could alter the biological control of parasitoid Psyttalia concolor Szepligeti (Hymenoptera: Braconidae) on the key pest Bactrocera oleae Rossi (Diptera: Tephritidae). Psyttalia concolor adults can be contaminated by exposure to spray droplets, contact with treated surfaces or oral uptake from contaminated food sources. Pesticides impact both pest and parasitoid populations when they coexist in time and space, as they reduce pest numbers available for parasitoids and might cause toxic effects to parasitoids from which they need to recover. Therefore, the appropriate timing and application of selective chemical treatments provides the opportunity to incorporate this parasitoid in the IPM of B. oleae. This manuscript reviews the current literature on lethal and sublethal effects of insecticides, fungicides, herbicides, and biopesticides on P. concolor. Insecticides were generally more toxic, particularly organophosphates and pyrethroids, while herbicides and biopesticides had less effects on mortality and reproductive parameters. Some fungicides were quite harmful. Most of the studies were conducted in laboratory conditions, focused on reproduction as the only sublethal effect, exclusively considered the effect of a single pesticide and persistence was hardly explored. Field studies, currently quite scarce, are absolutely needed to satisfactorily assess the impact of pesticides on P. concolor.