Correlation of weather parameters on the seasonal incidence of Helicoverpa armigera infesting Cicer arietinum

Abstract

Investigation taken up on the seasonal occurrence of Helicoverpa armigera, on Cicer arietinum L., revealed the presence of H. armigera from the 51st to 12th Standard Meteorological Week (SMW). Number of larvae found per plant ranged from 0.14 to 4.28. The larval population began to appear during the 51st SMW, with a mean of 0.66 larvae per plant and steadily increased until reaching its peak during the 6th SMW with a mean of 4.28 larvae per plant. Subsequently, the population declined, reaching a mean of 0.14 larvae per plant by the 12th SMW. The larval population of H. armigera displayed a highly significant negative correlation with both the maximum (r = -0.670**) and the minimum temperature (r = - 0.665**).