Predatory Efficiency of Geocoris pallidipennis (Hemiptera: Geocoridae) on Eggs and Early Instars of Helicoverpa armigera

Abstract

The cotton bollworm, Helicoverpa armigera, is a highly polyphagous pest causing severe yield losses in several agricultural crops, necessitating effective biological control strategies. The present study evaluates the predatory efficiency of Geocoris pallidipennis (Hemiptera: Geocoridae) on eggs and early instar larvae of H. armigera under laboratory conditions. Predator adults and nymphs were exposed to varying densities of prey stages, and parameters including predation rate, feeding preference, functional response, and consumption efficiency were recorded. Results indicated that both nymphs and adults of G. pallidipennis actively preyed upon eggs and first- and second-instar larvae, with higher consumption rates observed for egg masses. Predation efficiency increased with prey density up to a saturation point, indicating a type II functional response. Nymphal stages exhibited relatively higher feeding rates compared to adults, suggesting greater energetic demand during development. The predator demonstrated a strong preference for early developmental stages of H. armigera, which are more vulnerable and less mobile. Environmental conditions such as moderate temperature and adequate humidity enhanced predator activity and feeding performance. The study also observed significant reduction in prey survival and delayed population development under predator exposure. These findings highlight the potential of G. pallidipennis as an effective generalist predator in integrated pest management programs targeting H. armigera. Its ability to suppress early pest stages is particularly valuable for preventing crop damage at initial infestation levels. Overall, the results demonstrate that G. pallidipennis exhibits strong predatory potential and can contribute significantly to sustainable pest suppression in agroecosystems when conserved and integrated into biological control strategies.