Population dynamic of cotton leafhopper, Amrasca devastans (Homoptera: Jassidae): A review

Cotton leafhopper, Amrasca devastans has become very serious pest in recent years. Both nymphs and adults suck the sap from under surface of the leaf causing specking symptoms, crinkling and distortion of leaves and reddening all along the sides of leaves with downward curling. A. devastans caused significant damage during early stage by sucking the cell sap of the cotton leaves. The incidence of leafhopper was recorded from 23^rd SMW to 38^th SMW at seven days interval. The maximum leafhopper population on RCH 650 BGII Bt (2.26/ leaf) was found during 33^rd SMW and on H-1098-i non-Bt (1.89/ leaf) was found during 32^nd SMW. Throughout the season the leafhopper incidence was found lower than the economic threshold in H-1098-i non-Bt. Nymphal population exhibited significant positive correlation with relative humidity and rainy days.