Population Dynamics of Coccinella septumpunctata L. (Coleoptera: Coccinellideae)in Cotton Ecosystem in Relation to Environmental Factors

The population dynamics of the lady bird beetle (LBB), Coccinella septumpunctata L. (Coleoptera-Coccinellideae) inrelation to climatic factor was studied in two consecutive cropping seasons, 2005–06 and 2006–07. The study revealed that, the cotton LBB was first recorded in the 27^th SMW i.e. first week of July during both the years of study and remained active till 50^th SMW (IInd week of December). The peak population was observed (9.76/5 plant) during 37^th SMW i.e. 3rd week of September. The correlation studies between Population of LBB and weather factors revealed that the its population had a significant positive correlation with maximum temperature (0.542) & minimum temperature (0.560). The multiple coefficient value between the LBB population and group of variable clearly indicated that 79.50% change in LBBpopulation were affected by weather factors. The data also revealed that 20.50% variation in population was caused by inexplicable reasons or due to error beyond the control of experiment or due to factors not included in the investigation. Path coefficient analysis of LBB population and abiotic factors revealed that the minimum temperature had positive and high direct effect (1.6592) followed by morning relative humidity(0.1972), rainfall (0.1535), and sunshine hours (0.1519) and evening relative humidity (0.016) respectively.