Sublethal Effects of Commonly Used Insecticides in Tomato Crop on Functional Response and Biological Parameters of Macrolophus pygmaeus Rumber (Hemiptera: Miridae)

The hemipteran, Macrolophus pygmaeus Rumber, is an effective biocontrol agent against many crop pests including tomato leaf miner, Tuta absoluta Meyrick. Sublethal effects of azadirachtin (Neem Azal®), indoxacarb (Avaunt®), and emamectin benzoate+lufenuron (Proclim Fit®) were studied on biological characteristics and functional response of the predatory bug in laboratory conditions at 25±1°C, 6 ±5% RH, and a photoperiod of 16:8 hour (L:D). For this purpose, females of the predatory bug were exposed to sublethal residues (10% of field concentration) of the insecticides. Two-sex life table and Rogerchr('39')s model were used to investigate effects of the insecticides on biological parameters and functional response of the predator, respectively. Results indicated that sublethal residues of indoxacarb and azadirachtin had the highest and lowest side effects on life table parameters of M. pygmaeus. Whereas azadirachtin has no significant effects on the bug biological parameters, total fecundity and longevity of the bug in indoxacarb treatment were significantly lower (14.6%) and higher (6.9%) than the control. The predator showed type III functional response. The type of functional response was not affected by the insecticide residues. However, the coefficient of attack rate (b) for the indoxacarb treatment (0.1521) was significantly lower than for other treatments. However, there was no significant difference between the handling Times (Th) of the treatments. In conclusion, the experiments proved that azadirachtin is a low risk insecticide to M. pygmaeus, which can be integrated with biological control by the predator.