Development of a bioinsecticide derived from dehydrated neem (Azadirachta indica a. juss) leaf extract and green coconut husk liquid (Cocos nucifera L.)

Abstract

Objective: to develop and evaluate the efficacy of a bioinsecticide formulated from the aqueous extract of dehydrated neem leaves (Azadirachta indica), supplemented with green coconut husk liquid (LCCV) as an adjuvant. Method: The insecticide formulation was evaluated for its effectiveness against sucking insects Aphis gossypii and Dactylopius coccus in lemon and eggplant crops, alongside evaluations of foliar sensitivity. Bioinsecticide formulations composed of 10, 20, 50, 80, and 90% neem extract combined with 90, 80, 50, 20, and 10% LCCV, respectively, were sprayed onto infested plants. Seven
days after application, leaf integrity, phytotoxicity, and pest mortality rates were recorded. Results: The bioinsecticide exhibited strong inhibitory effects on insect gastrointestinal function, impairing development, growth, fertility, fecundity, and ultimately inducing mortality. The formulation containing 90% neem extract and 10% LCCV demonstrated the highest efficacy. Chemical characterization revealed higher protein content in the pure neem extract relative
to the combined formulation, reflecting the influence of tannins, phenolics, and secondary metabolites from LCCV. Soluble carbohydrate levels decreased in the mixed bioinsecticide; however, a substantial amount was retained, indicating preserved biological potential. Infrared spectroscopy confirmed the chemical profiles of the extracts and suggested the formation of a new compound. Conclusion: Overall, the integration of neem extract with LCCV yielded a bioinsecticide with satisfactory insecticidal activity, supporting its potential as a biotechnological tool for the sustainable management of agricultural pests.