International Journal of Pure and Applied Zoology

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Evaluation of Nymphicidal Effect of Two Indigenous Plant Extacts on Cotton Pest, Dysdercus Cingulatus (Fab.)

Antifeeding effect varied concentrations of Adathoda vasica and Vitex negundo crude methanolic leaf extracts was evaluated against an economically important cotton pest, Dysdercus cingulatus (Fab.) (Hemiptera: Pyrrochoreidae). All the concentrations (0.2, 0.4, 0.6, 0.8 and 1.0%) tested effectively caused varied ranges of nymphal mortality in all instar groups. The results revealed that among two plant antifeedants, Vitex negundo caused more nymphal deaths. However, both plant extracts produced more than 50% nymphal mortality at two higher concentrations (0.8 and 1.0%). It was evident that earlier nymphal instars (II and III) were more susceptible than the late nymphal instars (IV and V) to both plant antifeedant concentrations. Presence of Alkaloids, Terpenoids and Phenolic compounds might be the reason for these activities. It is concluded that V.negundo possess both antifeedant and nymphicidal activities. It can be used for the management of sucking pests of agricultural crops.

Author(s): P. Ranilalitha, M. Sukumaran, S. Raveendran,A. Kavitha Amirthanayagi