Potential of Ethanol Extract of Kirinyuh Leaves (Chromolaena odorata L.) as a Botanical Biopesticide for Controlling Fall Armyworm (Spodoptera frugiperda J.E. Smith) (Lepidoptera: Noctuidae) on Maize Leaves (Zea mays L.) under Laboratory Conditions

Abstract

Maize (Zea mays L.) is a strategic cereal crop with high economic value in Indonesia. However, its productivity is frequently constrained by fall armyworm (Spodoptera frugiperda J.E. Smith), an invasive pest that causes severe leaf damage and yield losses. Excessive reliance on synthetic insecticides may increase pest resistance, environmental contamination, and risks to human health; therefore, botanical insecticides are increasingly explored as safer alternatives. This study evaluated the potential of ethanol extract of kirinyuh leaves (Chromolaena odorata L.) as a botanical biopesticide against second-instar S. frugiperda larvae on maize leaves under laboratory conditions. The experiment was arranged in a completely randomized design with six treatments, consisting of a control and kirinyuh leaf extract concentrations of 2%, 4%, 6%, 8%, and 10%, with four replications. Maize leaves were treated using a leaf-dip bioassay, and larval mortality was observed every 24 h for 168 h after application. The effects of the extract on pupal and adult abnormalities were also recorded. The results showed that kirinyuh leaf ethanol extract significantly affected larval mortality and insect development. The highest larval mortality was obtained at 10% extract concentration, reaching 50% at 168 h after application. The extract also disrupted metamorphosis, with the 2% concentration producing the highest pupal abnormality (47.5%), whereas the 4%, 8%, and 10% concentrations produced 2.5% abnormal adults. These findings indicate that kirinyuh leaf ethanol extract has moderate insecticidal and developmental-disrupting activity against S. frugiperda, but further optimization of concentration, formulation, and application frequency is required before practical field use.