2.6. Larvicidal bioassay of NPs

Mosquito larvicidal activity assay of the green synthesized NPs was performed as described by WHO (2005)). Larvicidal bioassay experiment was carried out at room temperature (27 ± 2 °C). Twenty five 4th instar mosquito larvae of A. aegypti were introduced into 250 ml of filter sterilized tap water and the photoperiod was adjusted as 18:6h light and dark cycle. The larvicidal activity of the silver NPs was determined after incubation of 24 h. NPs were mixed in aqueous solution and diluted and a control experiment (aqueous plant extract) was also performed in triplicate analysis. After every 4 h, mortality of larvae was observed and dead larvae were removed from the experimental container. The mortality of larvae was finally corrected as suggested by Abbott (1925).