Efficacy of medicinal plant extracts against malarial vector, Anopheles subpictus Grassi

Insecticides of botanical origin may serve as suitable alternative biocontrol techniques in the future. The aim of this study was to evaluate the adulticidal activity and adult emergence inhibition (EI) of leaf hexane, chloroform, ethyl acetate, acetone, and methanol extracts of Aegle marmelos (Linn.) Correa ex Roxb, Andrographis lineata Wallich ex Nees., Andrographis paniculata (Burm.f.) Wall. ex Nees., Cocculus hirsutus L. Diels, Eclipta prostrata L., and Tagetes erecta L. tested against malarial vector, Anopheles subpictus Grassi (Diptera: Culicidae). All plant extracts showed moderate adulticidal activity and EI effects after 24 h of exposure at 1,000 ppm; however, the highest adulticidal activity was observed in ethyl acetate extract of A.lineata, chloroform extract of A.paniculata, acetone extract of C.hirsutus, and methanol extract of T.erecta (LD50 = 126.92, 95.82, 109.40, and 89.83 ppm; LD90 = 542.95, 720.82, 459.03, and 607.85 ppm); and effective EI was found in leaf acetone extract of the A. marmelos, ethyl acetate extract of A.lineata, methanol extracts of C. hirsutus, and T.erecta, (EI50 = 128.14, 79.39, 143.97, and 92.82 ppm; EI90 = 713.53, 293.70, 682.72, and 582.59 ppm), respectively, against A. subpictus. These results suggest that the leaf methanol extract of C. hirsutus and T.erecta have the potential to be used as an ideal eco-friendly approach for the control of A. subpictus. Therefore, this study provides first report on the mosquito adulticidal activity and EI of plant extracts against malaria vector.