Seasonal Abundance of Insect Pests against Forage Cowpea

The seasonal abundance study of cowpea aphid showed increasing trend upto middle of August, 2011. Thereafter, population of cowpea aphid decreased and lowest population was noticed during last week of August, 2011. Henceforth, population of cowpea aphid showed increasing trend and reached to its peak during 3^rd week of October, 2011. Infestation of cowpea aphid showed negative correlation with minimum temperature and evening relative humidity and positive correlation with maximum temperature. Population of jassids was noticed in the 1^st week of August, 2011. Thereafter, population of jassids started increasing and suddenly decreased and was to its lowest value during last week of August, 2011. Thereafter, population of jassids showed increasing trend and reached to its peak during 3^rd week of October, 2011. The population of jassids showed negative correlation with minimum temperature and evening relative humidity and showed positive correlation with maximum temperature. The infestation of semilooper on forage cowpea was noticed during 3^rd week of August, 2011 and reached to its peak in next week. The semilooper population showed negative correlation with rainfall. Lady bird beetles were active throughout the crop season; initial population was noticed during 2^nd week of August, 2011. The lady bird beetle population was negatively correlated with minimum temperature and evening relative humidity and positively correlated with cowpea aphids.