Management of Insect-pests Population in Black Gram with Novel Insecticides and Their Natural Enemies

Abstract

A Field experiment were carried out at Entomology Instructional Farm, JNKVV- College of Agriculture, Rewa (M.P.) during Kharif on Black gram variety T-9. The initiation of white fly infestation was recorded in the 2^nd week of August and reached a peak level 10.84 per five leaves in the 2^nd week of September when the temperature ranged between 20.6-29.9°C & RH 70-99%. Correlation coefficient values for white fly incidence and weather parameters showed that maximum and minimum relative humidity besides minimum temperature had positive correlation but maximum temperature and rainfall showed negatively correlation with white fly population. While, Bihar hairy caterpillar first appearance was recorded in the 4^th week of August and reached a peak level 10.44 larvae/mrl in the 4^th  week of October when the temperature ranged between 15.1-30.7°C & relative humidity 62-96%. Correlation coefficient values for Bihar hairy caterpillar incidence and weather parameters showed that maximum temperature had positive correlation and minimum temperature, maximum & minimum relative humidity besides rainfall had negative influence on Bihar hairy caterpillar population. To evaluate the efficacy of new molecule of insecticides i.e. Flubendiamide 39.35% SC, Indoxacarb 15.8% EC, Thiomethoxam 25% WG, Triazophos 40% EC, Monocrotophos 36% SL, Thiacloprid 21.7% SC, Chlorantraniliprole 18.5% SC and Quinalphos 25% EC and compared with untreated control plot against the Bihar Hairy Caterpillar, Spilosoma obliqua Walker and White fly, Bemisia tabaci Gennadius. Thiacloprid 21.7% SC was found most effective against white fly followed by Thiomethoxam 25% WG while Chlorantraniliprole 18.5% SC was found most effective against Bihar Hairy Caterpillar. The highest yield of 1012.3 kg/ha, was recorded in the plot treated with Chlorantraniliprole 20 g a.i. /ha. The natural enemies were recorded from the black gram cultivars during seedling to podding stage of the crop during Kharif season which indicated the incidence of eight species of insect pests and six species of natural enemies on the crop were observed under the agro-climatic condition of Vindhaya region.