Bioinsecticide activity of ethyl acetate extract of Nothaphoebe coriacea Kosterm bark against Spodoptera exigua larvae in a laboratory

Abstract

Spodoptera exigua is a cosmopolitan and polyphagous pest. Botanical pesticides are an alternative technique to control S. exigua. This study aimed to evaluate the effect of an ethyl acetate extract of Nothaphoebe coriacea Kosterm bark (EEN) on the biological activity of S. exigua larvae and to determine the most effective concentration to manage S. exigua. This experiment was arranged on a single factor completely randomized design with the concentration level as a factor. Botanical pesticide formulated from ethyl acetate solvent in maceration extraction. The test was carried out by dipping the leaf mustard into the treatment solution and then feeding it to 10 S. exigua larvae. The result showed the EEN had an 0.5% extract content with bioactive from the alkaloids and tannins groups. Mortality and feeding inhibition showed good responses to the biological activity test. However, the mortality rate test revealed different responses the most effective concentration of EEN was 0.5%. This concentration has a mortality of 92% and kill 3.6 individuals per hour, but has a low feeding inhibition of 72.82%. A botanical pesticide from EEN can be developed to control S. exigua. The LC50 obtained from the application of the EEN to S. exigua larvae was 0.062%. EEN has the potential to be developed as a botanical pesticide.