Insecticide compatibility with abundance and diversity of predatory fauna in wheat (Triticum aestivum) ecosystem

Abstract

Assessment of the potential effects of insecticides on the natural enemies is an important part of IPM. The use of natural enemies in combination with selected insecticides which have no effect on them is effective in depressing the population density of the insect pest. In this context, an effort was made to know the diversity of predatory fauna and effect of seed dressers, soil applied chemicals and foliar spraying insecticides on their abundance in wheat during rabi, 2019-20. The investigation registered the activity of green lacewing (Chrysoperla sp.), coccinellids (Coccinella transversalis, Cheilomenes sexmaculata, Illeis cincta), syrphids and spider (Oxyopes sp.). Meanwhile, the results also revealed the peak activity of green lacewing, coccinellids, syrphids and spiders in seed treatment with thiamethoxam 30 FS @ 5 ml/kg seeds (1.20, 1.40, 0.73 and 0.67 per meter square area, respectively) followed by soil application of carbofuran 3G @ 30 kg/ha (1.17, 1.37, 0.70 and 0.62 per meter square, respectively) and both were found on par with untreated check (1.39, 1.51, 0.81 and 0.78 per meter square, respectively). Whereas, the least population was recorded in soil application of carbofuran 3G @ 30 kg/ha followed by a foliar application of cypermethrin 10 EC @ 0.5 ml/l (0.22, 0.24, 0.14 and 0.12 per meter square, respectively) over rest of the treatments. These results endorsed the biocompatibility of seed dressers (Thiamethoxam 30 FS), soil applied chemicals (Carbofuran 3G) and detrimental effects of foliar spraying insecticides (Cypermethrin 10 EC, Emamectin benzoate 5SG and Nimbecidine 1500 ppm) on population dynamics of natural enemy.