Vol. 2, Issue 1, Part A (2015)

Author(s): Siva Kamalakannan, Kadarkarai Murugan, Balamurugan Chandramohan

Abstract: The methanolic leaf extracts of Acalypha alnifolia and Vitex negundo were studied for IGRs activity against Aedes aegypti. The developmental bioassay using standard WHO protocol was tested for larval, pupal and adult development activity against freshly emerged first instar larvae of A. aegypti followed by the standard procedure. Effect of A. alnifolia showed (L1 to L4) prolonged larval duration and up to 8 days at 500 ppm. Whereas, control was reached up to 4 day of complete larval development. Effect of A. alnifolia showed (L1 to L4) prolonged larval duration and up to 8 days at 500 ppm. Whereas, in control complete larval development was completed in 4 days. Similarly, methonolic extract of V. negundo was prolonged larval (L₁ to L₄) duration up to 3 to 5 days at 500 ppm concentration than the control. Combined treatment of both extracts showed higher significant prolongation of larval, pupal and adult duration and was reached up to 7 days. The adult emergence period was extended to 28 days, whereas, in control it was reached to 12 days. Hence, the present study clearly showed that larval, pupal and adult emergence was greatly inhibited by the present active compound in the plants.