Susceptibility of pupal and adult stages of the parasitoid Lysiphlebus fabarum Marshall (Hym.: Braconidae) to insecticides thiacloprid+deltamethrin, pirimicarb and pymetrozine

Lysiphlebus fabarum Marshall,an endoparasitoid of the black bean aphid, Aphis fabae Scopoli is an important component of integrated pest management of this pest and it is necessary to study its interaction with insecticides used against this pest. In this study, the lethal effects of recommended concentrations of three insecticides, thiacloprid痩浪枭蚸, pirimicarb and pymetrozine were investigated on pupal and adult stages of the parasitoidunder laboratory conditions. The pupae and the adults were exposed to insecticides with mummy dipping and dry residues of insecticides on glass plates methods, respectively. Thiacloprid痩浪枭蚸 and pirimicarb significantly caused mortality rates in pupal and the adult stages, while pymetrozine had no significant effect. According to International organization for biological control (IOBC)(toxicity of insecticides), thiacloprid痩浪枭蚸 at the pupal and the adult stages were classified as moderately harmful (class 3) and harmful (class 4), respectively. Pirimicarb was also classified as slightly harmful (class 2) and harmless (class 1), respectively. Pymetrozine in the two tested stages were classified as harmless (class 1). In this study, the persistent toxicity of insecticides against the adult wasps was also investigated under semifield conditions. According to the IOBC (persistence) classification, thiacloprid痩浪枭蚸, pirimicarb and pymetrozine were classified as moderately persistent (class C), slightly persistent (class B) and short lived (class A), respectively. According to the present study, pymetrozine and pirimicarb had low side effects on L. fabarum at the pupal and adult stages, but thiacloprid痩浪枭蚸 caused deleterious effects on this parasitoid at two stages tested.