In the present study, selected some plants, namely, Andrographis paniculata Ness., Cardiospermum halicacabum L., Cassia tora L., Catharanthus roseus L (G) Don., Datura metal L., Eupatorium riparium and Mikania micarantha were screened for their larvicidal and antifeedant activity against the larvae of Helicoverpa armigera (Hubner) under laboratory conditions. The crude extracts of all the selected plants demonstrated a dose dependent increase in bioactivity. However the bioactivity of four plants namely, A.paniculata, Cassia tora L., C.halicacabum L., and Datura metal L. was significantly higher (p ≤ 0.05) than the control and extracts of C.roseus, E. riparium and M.micarantha. Methanol extract of A.paniculata caused highest oral toxicity with larval mortality ranging between 29.00% and 58.22% across the test concentration (0.2%, 0.4% and 1% w/v) while extract of C.tora L., demonstrated the highest feeding deterrence with reduction in larval feeding by 59.92% and 76.61% at 0.2% and 0.4% respectively. Crude extract of C.halicacabum L., leaves demonstrated high oral toxicity and feeding deterrence while extract of D.metel showed moderate level of oral toxicity as well as feeding deterrence at the highest tested concentration. Thus it may be concluded that four out of the selected plants possess insecticidal property and can be further investigated for the development of a potent natural botanical insecticide.
Feeding deterrence towards Helicoverpa armigera by Tithonia diversifolia tagitinin C-enriched extract
