Investigation on key mortality factors of Helicoverpa armigera (Hubner) on pigeonpea and chickpea

Abstract

The key mortality factors of Helicoverpa armigera (IIubner) on pigeonpea and chickpea were determined during the 2004-05 and 2005-06. The different life stages of H. armigera were collected from these crops and reared under laboratory conditions to observe the parasitization. The results revealed that Eriborus argenteopilosus was the dominant parasitoid contributing 20.73 and 18.95% early instar larval population loss at initial period of infestation i.e., in November on pigeonpea and chickpea, respectively. Similarly, Bracon species also showed its activity at early period of pest activity (November), while Campoletis chlorideae recorded maximum parasitization in the peak period of infestation on both the crops. The total parasitization of early larval instar was 29.27 and 26.32% in November and December on pigeonpea and chickpea. Tachinid fly was found mainly associated with the mortality of late life stages and suppressed 9.84 and 12% population of late instar larvae in December and January on pigeonpea and chickpea, respectively. Moreover, HaNPV susceptibility was also noted in early and late instar larvae on both the hosts. In pupal stage, Tachinid fly contributed 14.94 and 20% reduction in H. armigera population in December and January on pigeonpea and chickpea, respectively.