effects of imidacloprid, dichlorvos, pymetrozine and abamectin, on life table parameters of the predatory bug, orius albidipennis (hemiptera: anthocoridae)

effects of four pesticides (imidacloprid, dichlorvos, pymetrozine and abamectin) were evaluated on life table parameters of orius albidipennis (reuter). pesticides were used at the concentrations recommended by the manufacturers. the bioassays were carried out using drum-cell method, in a growth chamber at 27 â± 1âºc, r.h. of 65 â± 5% and 16 h photo phase. the net reproductive rate (r0) value for the populations treated with imidacloprid, dichlorvos, pymetrozine, abamectin and tap water as control was, 2.91 â± 0.48, 18.85 â± 2.55, 10.16 â± 1.21, 8.00 â± 1.05, 43.40 â± 7.64; the intrinsic rate of natural increase (rm) was 0.040 â± 0.005, 0.097 â± 0.018, 0.086 â± 0.012, 0.078 â± 0.010, 0.148 â± 0.006: the mean generation time (t) was 25.60 â± 1.12, 25.94 â± 1.85, 26.37 â± 0.25, 25.61 â± 0.21, 25.20 â± 1.16; the doubling time (dt) was 18.04 â± 2.76, 7.72 â± 1.60, 8.23 â± 1.11, 9.24 â± 1.37, 4.68 â± 0.18, and the finite rate of increase (î») was 1.041 â± 0.006, 1.102 â± 0.019, 1.090 â± 0.013, 1.081 â± 0.011, 1.160 â± 0.007, respectively. imidacloprid and dichlorvos, which revealed the most and the least effects on the life table parameters, were the most and the least harmful among the chemicals tested.