ABSTRACT
Helicoverpa armigera (Hiibner) is a key pest of cotton, pulses, vegetables and cereals. In India, it has been recorded on more than 181 plant species from 45 plant families (Manjunath et al. 1989). It is the single most important cause of yield losses in several crops. Despite considerable research effort, its pest status may actually be increasing. Several factors, including increasing levels of resistance to pesticides and rise in cropping intensity has contributed to greater importance of H. armigera (Shanower et al. 1998). The key pest status of H. armigera is due to a combination of factors. Helicoverpa armigera larvae preferentially feed on reproductive structures. These nitrogen-rich structures provide enhanced growth and fecundity relative to feeding on vegetative parts. In addition, H armigera is highly fecund, feeds on a diverse array of host plants, is a strong disperser, and undergoes facultative diapause (Fitt 1989). All of these life history features contribute to make H. armigera one of the 'world's worst pest (Pimbert et al. 1989).
