Incidence of Aphid and Whitefly on Chilli and their Management using Biorational and New Generation Insecticides

An experiment was conducted at Entomology field laboratory, Bangladesh Agricultural University, Mymensingh during the rabi season of 2019-2020 to investigate the incidence of aphid and whitefly on chilli and effect of some biorational and new generation insecticides for controlling those insects. The presence of aphids was first identified on 2nd week of January at the vegetative stage of the chilli plant with the density of 2.34 per leaf. Then a gradual increase and a subsequent decrease were observed in the aphid population. The population density was reached to the peak level by first week of February with the mean number of 16.69/leaf. Thereafter, the population decreased in a gradual manner and reached to the minimum level by the end of 3rd week of March. In case of whitefly, similar trend of incidence but comparatively lower incidence was recorded from seedling to fruiting stage. On the other hand, five biorational and new generation insecticides were evaluated against these insects in field condition. All tested insecticides were found very effective except Shurter 505 EC (Cypermethrin + Chlorpyriphos) regarding reduction of aphids and whitefly populations, curled leaf development and increases of yield of green chillies. Among rest of the four insecticides, the Imixam 70WDG @ 0.30 g/L water (Imidacloprid + Thiamethoxam) was found most effective that was significantly followed by 0.20 g/L. This findings was closely followed by Gain 20 SL (Imidacloprid), Lumectin 10WDG (Lufenuron + Emamectin Benzoate) and Biotrin 0.5% (Matrine) respectively considering all the parameters studied.