Oviposition and larval establishment of three ‘generalist’ noctuids on Capsicum annuum

Abstract

Understanding the oviposition and foraging behaviour of pestiferous lepidopterans on their economically important food plants guides the development of effective pest management tactics. Here, we examined the oviposition behaviour and larval establishment of three noctuid species on a single crop—capsicum (Capsicum annuum). We selected pest species that are known to infest capsicum crops to varying degrees—the cotton bollworm, Helicoverpa armigera; the cluster caterpillar, Spodoptera litura; and the fall armyworm, Spodoptera frugiperda. Although related, these species differ in their known host-plant preferences and larval feeding behaviour. We conducted a series of glasshouse experiments examining moth oviposition and larval survival on different crop stages and the ability of neonate larvae to feed and establish on capsicum fruits at different stages of development. Although all three species oviposited on capsicum plants, S. litura laid more eggs than the other species and targeted most of their eggs to plants rather than the cage wall, indicating a preference for the plant. S. litura larvae demonstrated the highest level of survival (48%) when left unrestricted on capsicum plants, whereas only a small proportion of S. frugiperda (12%) and H. armigera (3%) larvae survived on capsicum plants. Surprisingly, most surviving S. frugiperda larvae were found feeding inside capsicum fruits. The results generated in this study demonstrate how in-field infestations of these noctuids in capsicum arise and will guide further development of pest management strategies for these pests in capsicum.