Insect Growth Regulatory Activity of Vinca rosea and Callistemon lanceolatus extracts against Helicoverpa armigera (Hüb.)

Leaf extracts of Vinca rosea and Callistemon lanceolatus alone and their mixtures proved effective in terms of % growth reduction, larval toxicity as well as inhibition of normal adult emergence of Helicoverpa armigera. At higher concentrations of methanolic extract of V. rosea, highest number of larval pupal intermidiates was observed. There was a prolongation of larval and pupal duration of 19.50 and 18.00 days as compared with control (17.48 & 15.06 days), respectively. The larvae fed on leaves treated with 1:3 mixtures of both plant extracts required 26.8 and 22.0% additional days over control to reach the pupal and adult stages, respectively. Both the plant extracts and their mixtures in all the cases were found superior than the neem oil and NSKE.