Insecticidal Activity of Annona squamosa and Annona muricata Ethanolic Leaf Extracts against Scotinophara coarctata

Abstract

The use of conventional insecticides has raised some concern about their threat to the environment and development of insecticide resistance in insects. Making alternative insecticides from plant extracts has been long suggested to control insects. In this study, toxicity and insecticidal activity of ethanolic leaf extract of Annona squamosal and Annona muricata against Scotinopharacoarctatawere investigated. Leaves of A. squamosal and A. muricata were collected, dried and macerated in 95% ethanol. The macerated samples were filtered and squeezed to obtained the extracts and were placed in beakers. The solvent was then removed by evaporation and concentrated in a water bath. Different concentrations (1ppm, 10ppm,100ppm and 1000 ppm) were prepared through serial dilution. Five replications were done for each concentration. The preliminary phytochemical investigation was carried out to identify the various constituents present in the extracts. Cytotoxicity was evaluatedregardingLC50, and Glass-vial Assay was conducted to test its insecticidal activity against adult S. coarctata. The phytochemical test revealed the presence of alkaloids, coumarin, flavonoids and phenol on both leaf extracts. However, the presence of saponins was only found in A. squamosa, and the occurrence of Quinonewas only found in A. muricata. LC50of A. muricata ethanolic extract using BSLA and GLA were identified at159 ppm and 62ppm while A. squamosahadan LC50of 32ppm and 8 ppm respectively. Maximum mortalities (100%) for both extracts were observed at 1000-ppm concentration. These results suggested that A. squamosaandA. muricata have a good potential for development as a botanical insecticide for eco-friendly management against S. coarctata.