LARVICIDAL ACTIVITY OF INDIGENOUS PLANT AQUEOUS EXTRACTS ON MALARIAL VECTOR, ANOPHELES SUBPICTUS GRASSI (DIPTERA: CULICIDAE)

Mosquito control is facing a threat due to the emergence of resistance to synthetic insecticides. Insecticides of botanical origin may serve as suitable alternative bio control techniques in the future. The purpose of the present study is to assess the effect of leaf cold andHot water extracts of Ocimum basilicum,Ocimum  americanum,Cleome gynandra and  Passiflora foetida. All plant extracts showed moderate toxic effect on larvae after 24 h of exposure at 1,000 ppm;however, the highest larvicidal mortalityactivity was observed after 48 hcold water extracts of C.gynandra (LC₅₀=135.86, 155.58 and121.61ppm), (LC₉₀=594.12 720.87and 471.34 ppm ) andP.foetida, (LC₅₀=140.60, 161.38 and126.72ppm), (LC₉₀=628.20 and 784.14–498.75ppm) and  hot water extracts of O. americanum(LC₅₀=85.10, 89.40 and 67.19 ppm),(LC₉₀ =364.12, 468.20–375.12ppm), and C.gynandra, (LC₅₀=167.82, 189.75and148.12ppm) (LC₉₀ = 630.41, 782.11and492.94 ppm), and the overall findings of the present study have shown that the leaf aqueous plant extracts have the potential to be used as an ideal ecofriendly approach for the control of the A. subpictus. The screening results suggest that the cold water extract of C.gynandra, and hot water extract of O. americanumare promising in mosquito control.

Key Words:Anopheles subpictus, plant extracts, cold and hot water, larvicidal  activity