Vol. 11, Issue 11 (2022)

Field experiment conducted to study the impact of weather parameters on the population buildup of different lepidopteron pests of pigeonpea yielded a good amount of information. The peak population of gram pod borer, Helicoverpa armigera was observed during 45^th SMW (5-11 Nov.) with 3.8 moths / trap / week. Whereas, the peak population of tobacco caterpillar, Spodoptera litura was observed during 40^th (1-7 Oct.) and 1^st (1-7 Jan, 2019) SMW with 101.0 and 108.0 moths / trap / week, respectively. The fall armyworm, Spodoptera frugiperda population was more (10.0 moths/trap/week) during 40 SMW (1-7 October). Peak larval population of H. armigera, spotted pod borer, Maruca vitrata and S. litura was observed during 47^th, 49^th and 42^nd SMW with 4.8, 4.8 and 4.0 larvae/plant, respectively. However, there was no larval population of S. frugiperda on redgram. Further, significant correlation was obtained between adult trap catch of S. litura and wind speed with correlation coefficient (r) being -0.521; adult trap catch of S. frugiperda and max. temp., mean temp. RH II and Evaporation with correlation coefficient (r) being 0.616, 0.512, -0.526 and 0.584, respectively; and adult trap catch of H. armigera and RH-II with correlation coefficient (r) being -0.431. Similarly, moderately significant correlation was obtained between larval population of M. vitrata and max. temp., RH I, RH-II, Sun shine hours and evaporation with correlation coefficient (r) being -0.527, -0.588, 0.744, -0.709 and -0.553, respectively; larval population of S. litura and max temp., mean temp. and evaporation with correlation coefficient (r) being 0.493, 0.447 and 0.406, respectively; and larval population of H. armigera and RH-I and wind speed with correlation coefficient (r) being 0.319 and 0.304, respectively.