Ovicidal, larvicidal and pupicidal potential of neem seed kernel extract against Aedes aegypti L

Aedes aegypti is responsible for the spread of various public health diseases and mostly synthetic insecticides are being used for its control. However, regular and over use of these substances has lead to mosquito resistance and environment contamination. Plant based products are natural alternatives to replace the commercial synthetic insecticides. This study was conducted to assess the ovicidal, larvicidal and pupicidal potential of the extract prepared from dried neem seed kernels against Aedes aegypti . Larvicidal activity of neem seed kernel extract (NSKE) was tested using five different concentrations viz., 100, 200, 300, 400 and 500 ppm against all four instars of Ae. aegypti . Ovicidal and pupicidal activity was evaluated by exposing fresh viable eggs and pupae to three concentrations of NSKE, below its effective larvicidal concentration i.e. 200, 300 and 400 ppm. Calculated values for LC 50 were recorded as 49.96, 66.39, 77.19 and 83.57 ppm and for LC 90 values were 186.53, 228.86, 286.69 and 358.02 ppm, respectively for LI, LII, LIII and LIV instars of Ae. aegypti till 48 hours of exposure to NSKE. Treatment of NSKE with 300 and 400 ppm showed 100% ovicidal activity and significant mortality of both male and female pupae in comparison to control sets. These results indicate that NSKE could be used as larvicidal, ovicidal and pupicidal plant based agent for the efficient control of Ae. aegypti in future.