Impacts of the pesticides imidacloprid,propargite, and pymetrozine on Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae): IOBC and life table assays

The effects of imidacloprid, propargite, and pymetrozine on the common green lacewing, Chrysoperla carnea (Stephens) were investigated in the laboratory, using the IOBC-system and the life table response experiment. Residual glass plate bioassays were carried out using two-day-old larvae at the Iranian maximum field recommended rate of each commonly used pesticide. All three tested pesticides produced significant adverse effects on pre-imaginal survival (p < 0.01). Imidacloprid had no significant effect on fecundity, but propargite and pymetrozin caused significant reductions (p < 0.05). According to the IOBC classification, imidacloprid was found to be harmless (E = 27.44%); propargite (E = 49.78%) and pymetrozine (E = 66.9%) were slightly harmful. Life table assays revealed that imidacloprid and propargite had no significant effects on the intrinsic rate of natural increase, while pymetrozine caused a 34% reduction in r _m value (p < 0.05). Propargite was non-toxic to C. carnea under the tested conditions. In the case of imidacloprid, using a glass plate as test substrate led to␣underestimation of its effects. The life table assay showed more adverse effects of pymetrozine than the IOBC method.