SEASONAL INCIDENCE OF TOBACCO CATERPILLAR, Spodoptera litura IN BLACKGRAM, Vigna mungo (Linn.) DURING Rabi 2021 AND ITS CORRELATION WITH WEATHER PARAMETERS

Field experiments were carried out to study the incidence of S.litura in blackgram during Rabi 2021 at Department of Entomology, Annamalai University, Annamalai Nagar. Highest larval incidence of S.litura on blackgram were noticed on 10th standard meteorological week (SMW) (3.91 larvae/mrl) followed by 9th SMW (3.87 larvae/mrl) and 8th SMW (2.85 larvae/mrl) and 7th SMW (1.72 larvae/mrl). Correlation between weather parameters on larval incidence of S.litura revealed that maximum temperature (0.547), minimum temperature (0.580) showed significantly positive association with mean larvae population of S.litura, whereas morning relative humidity (-0.175), evening relative humidity (-0.198) and rainfall (-0.389) were negatively correlated with mean larval population of S.litura. Regression model indicated that increase in 10C of maximum temperature or 10C of minimum temperature, 1% morning RH, 1% evening RH increased the mean larval population of S.litura by 0.045, 0.794, 0.0893 and 0.002 larvae/mrl during Rabi 2021 respectively.