Larvicidal activity of selected plant extracts against Aedes albopictus Skuse (Diptera: Culicidae)

Plant-based insecticides may serve as suitable alternative as biocontrol techniques in the future. The present study has explored the effect of ether extracts of Emblica officinalis, Ricinus communis, Acacia coucinna, Cinnamomum tejpata, Piper nigrum, Coriandrum sativum, Olea vera, Linum usitatissimum, Syzygium aromaticum and Nigella sativa against larvae of Aedes albopictus under laboratory conditions. Larvae were exposed to a range of concentrations of each extract. The larval mortality was assessed after 24 and 48 hours exposure and LC(50)s were calculated for each time interval. All extracts showed moderate larvicidal activity. The lowest LC50 was found in Coriandrum sativum, Nigella sativa and Syzygium aromaticum at a dose of 363.7 ppm, 377.5 ppm and 403.4 ppm, respectively, after 24 h exposure while the amount of extracts used reduced to 263.9 ppm, 300.8 ppm and 342.2 ppm, respectively, after 48 h. In terms of lethal time response again Coriandrum sativum, Nigella sativa and Syzygium aromaticum showed less time to produce 50% mortality (14.28, 17.77 and 17.99 h). These plants extracts are therefore promising as alternative to synthetic insecticides in mosquito control programmes. Thus providing the basis to use the plant extracts against Aedes albopictus.