Larvicidal activities of green silver nanoparticles synthesized using neem seed extract on housefly larvae

Abstract

The house fly is a significant public health insect which needs to be controlled with environmentally friendly strategies. Therefore, Nano-insecticides were de-veloped using biosynthesized silver nanoparticles derived from neem seeds. Bio-synthesized AgNPs neem seed (NS-AgNPs) was tested at four concentrations (25%, 50%, 75% and 100% V/V) with two modes of application (contact and fumigant) against housefly larvae. Synthetic insecticides (dichlorvos) and control were included in the treatments for comparison. The treatments were arranged in a complete randomized design with three replications. The percentage mortality of the test insect was determined with different hours of exposure (2, 4, 6, 8 and 24 hours). The biosynthesized AgNPs (NS-AgNPs) displayed dark brown colour with maximum absorbance obtained at 450 nm. NS-AgNPs exhibited significant larvicidal effects against housefly larvae meanwhile the lowest concentration (25%) had the least larvicidal effect against the studied insect while highest con-centration (100% v/v) resulted in highest significant mortality of the studied housefly larvae. Nano-insecticides applied through contact significantly killed faster than fumigant bioassay. However, the tested nano-insecticide had delayed effect on the studied larvae compared to dichlorvos. Therefore, biosynthesized AgNPs used as nano-insecticides can be incorporated into the housefly manage-ment program.