Seasonal Incidence of Jasmine Leaf Webworm, Palpita unionalis (Pyralidae: U. T. of Puducherry)

Abstract

The seasonal incidence of P. unionalis was studied under in situ and in light trap collections. Under in situ, the seasonal incidence of jasmine leaf webworm, P. unionalis was recorded at weekly intervals based on per cent leaf and bud damage respectively from February 2012 to January 2013. The damage by P. unionalis was higher during January 2013 (18.08%) and lower per cent damage was recorded during May 2012 (1.13%). The multiple regression coefficient of weather parameters under in situ against the incidence of leaf webworm, P. unionalis in terms of per cent leaf damage showed a positive correlation with morning relative humidity, bright sunshine hours and a negative correlation with the maximum and minimum temperature, evening relative humidity and rainfall. In the light trap collections of leaf webworm, P. unionalis moths, a positive correlation was observed with the evening relative humidity, bright sunshine hours and a negative correlation with the weather parameters viz., maximum and minimum temperature, morning relative humidity and rainfall.