Effect of Biotic and Abiotic Factors on Insect-Pests Population of Rape Seed-Mustard Crop

Abstract

The present investigation was carried out during Rabi, 2013–14 at Student's Instructional Farm of Narendra Deva University of Agriculture and Technology, Kumarganj, Faizabad (UP), India. The population of insects and predator namely mustard aphid (Lipaphis erysimi), mustard sawfly (Athalia lugens proxima), painted bug (Bagrada hilaris), cabbage butterfly (Pieris brassicae) and lady bird beetle (Coccinella spp.) fluctuate with biotic and abiotic factors at different growth stages of rapeseed-mustard crop. The cloudy weather conditions along with temperature in the range of 10–200 C and relative humidity of 82% favored the insects for its survival and multiplication. 9th to 10th std. week were observed favourable for the activity of predator and remained active till the availability of mustard aphid as a prey. Mustard sawfly was positively correlated with minimum temperature, relative humidity and negatively correlated with maximum temperature, sunshine hours. Mustard aphid on BSH-1 was negatively correlated with minimum, maximum temperature, rainfall and sunshine hours whereas, positively correlated with relative humidity. Cabbage butterfly was positively correlated with minimum, maximum temperature, relative humidity, whereas negative correlation with the sunshine hours on BSH-1.