Side effects of three pesticides on the black bean aphid parasitoid,Lysiphlebus fabarum (Marshall) (Hymenoptera: Aphidiidae)

In this study, the side effects of thiacloprid+deltamethrin, pirimicarb and pymetrozine applied atthe maximum recommended field rates were investigated on the thelytokous population ofLysiphlebus fabarum (Marshall) using the IOBC and the life table methods. Newly emergedfemales (less than 24 h) were placed in drum cells contaminated with dry residues of pesticides(distilled water in the control). Thiacloprid+deltamethrin was very toxic to L. fabarum; causing100% mortality. Pirimicarb produced significant adverse effects on the mortality and fecundity;while pymetrozin did not. According to the IOBC standards, thiacloprid+deltamethrin (E =100%), pirimicarb (E = 62.49%) and pymetrozine (E = 10.35%) were classified as harmful,slightly harmful and harmless, respectively. Life table assays revealed that intrinsic rate ofnatural increase (rm) value in thiacloprid+deltamethrin (50%) and pirimicarb (12%) weresignificantly reduced; while pymetrozine had no effect on the intrinsic rate of natural increase(rm). Both the IOBC and the life table assay methods showed that pymetrozine was not toxic toL. fabarum. Therefore, the use of this pesticide in the IPM of black bean aphid along with thisnatural enemy seems to be practicable.

کلیدواژه ها:

thiacloprid+deltamethrin ، pirimicarb ، pymetrozine ، life table ، IOBC