Incidence of leaf folder [(Cnaphalocrocis mendinalis (Guenee)] in relation to climatic conditions in the hilly tract of Jalpaiguri, West Bengal

Leaf folder infestation was initiated at about 33 standard meteorological weeks (SMW) attaining the maximum peak of abundance at about 39 SMW with two regular generations during single crop season. Significant positive correlation between maximum temperature (Tmax), minimum temperature (Tmin), average temperature (Tavg) was noted. Effects of temperature gradient (Tgr), maximum relative humidity(RHmax), humidity gradient(RHgr)and number of rainy days (Rday) were insignificant. Minimum relative humidity (RHmin) and number ofrainydays (Rday) imparted significant negative effect.