Modelling population dynamics of army worm (Spodoptera litura F.) (Lepidoptera: Noctuiidae) in relation to meteorological factors in Multan, Punjab, Pakistan

Abstract Weather plays a critical void in mediating abundance of armyworms. Forecasting under such instances becomes fundamental for monitoring and management of this notorious pest particularly in developing countries where management cost is very high. Population data was taken from different locations of district Multan from 2006- 2010 by Pests Warning Wing of Agriculture Department, Government of Punjab, Pakistan. Comparison of means of percent hot spots of armyworm revealed that armyworm population was at par during 2006-2010. Weather relation with Spodoptera litura F. abundance was summarized on the basis of Multivariate regression and correlation tactics. Multivariate regression analysis model unveiled coefficient of determination with armyworm abundance. Maximum temperature had significant negative impact on armyworm abundance while relative humidity had positive effect on armyworm population. Correlation analysis revealed that maximum temperature had negative correlation with armyworm abundance while relative humidity and rainfall had significant positive correlation on armyworm population during 2006-2010. Armyworm population build up initiated in the month of July and continued a constant threat till the end of cotton season. Hence management practices should be focused from the month of July and continued till the end of October.