Seasonal activity of major insect pest species of crops collected in light traps

Seasonal activity of seven species viz, Holotrichia consanguinea, Gryllus bimaculatus, Gryllotalpa orientalis, Hyblaea puera, Plusia chalcites, Spodoptera litura and Spilosoma obliqua were observed in trap catches operated in field (Kharif crop) regularly in considerable numbers were studied in Kharif season during the period June to October end (2017). Two to three peaks were observed in general, showing period of highest & lowest activity both. Seasonal changes in the activity of pest species in adult stage monitored by light trap catches (weekly total) operated by Mercury vapour as well as Ultraviolet light source have been shown in population graphs of both the light sources. These graphs show the comparative changes in populations with major peaks throughout the active season during the period June IV Week to October end.