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.

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The dissipation of malathion in 5% aqueous extracts of some fruits and vegetables including bell pepper, tomato, cucumber, cantaloupe, carrot, and also buffer (control) was investigated at 37 °C for 4 h. The dissipation trend of malathion in the fruit/vegetable samples and buffer followed first-order double-exponential decay (FODED) and simple first-order kinetic (SFOK) models, respectively. The initial dissipation rate of malathion in tomato (DT10=0.05 h), bell pepper (DT10=0.06 h), and carrot (DT10=0.07 h) was faster compared to the other samples. The slowest rate of pesticide decline belonged to cantaloupe (DT50=1.92 h) with a significant difference from the other samples (p≤0.01), whereas tomato (DT50=0.43 h) and carrot (DT50=0.53 h) showed the fastest dissipation rate. DT90 values derived from the models revealed no significant difference between the samples except for cantaloupe which had the slowest rate of dissipation (DT90=8.27 h) with a significant difference compared to others (p≤0.01). A direct correlation was observed between protein content of the samples and the rate of malathion decline which indicates the role of plant enzymes in degrading malathion residues.