Population dynamics of insect pests of Mung bean {Vignaradiata (L.) Wilczek) in Gangetic plains

摘要

Studies on population dynamics of insect pests during kharif season revealed that the population of jassids and whitefly were ranging from 0.4-3.4/cage and 0.2-5.2/cage, respectively. The jassids and whitefly appeared during 32 standard week with 0.4/cage and 0.2/cage, respectively. The jassids population exhibited a significant positive correlation with average relative humidity. The population of whitefly had significant negative correlation with maximum temperature and average temperature and positive significant correlation with age of crop. The thrips appeared in 35lh standard week ranging from 0.2-1.2/flower and had positive significant correlation with minimum and average relative humidity. The occurrence of blister beetle started on 35,h standard weeks (0.6/plant) and was positively significant with age of crop. The incidence of tobacco caterpillar started in 37th standard week which gradually increased till harvest of crop (3 larvae / plant). The tobacco caterpillar had significantly negative correlation with minimum temperature and positive correlation with age of crop. The epilachna beetle appeared during 34th standard week with intensity 0.6/plant and had significantly positive correlation with minimum and average relative humidity. The pod sucking bug was observed in 35"1 standard week with intensity (0.8/plant) and attained its peak in 38th standard week (6/plant)and had significantly negative correlation with minimum and average temperature and positively with age of crop. The population of spotted pod borer was ranging from 0.2 to 2.4 larvae per plant. The incidence of this pest started in 35 standard week and attended a peak 2.4 larvae/plant during 38 standard week. The correlation of spotted pod with weather factors exhibited significantly negative correlation with minimum and average temperature and highly significant with age of crop. Rests of the weather parameters were non - significantly correlated with the pest population.