104: Extraction and characterization of phytochemicals as posible biopesticide application

Abstract: Plant diseases and pests are among the primary threats limiting crop yields worldwide. The use of biological and chemical agents to inhibit pest and disease activity can enhance global food security by improving agricultural productivity. In the southeastern United States, West Coast, and Rocky Mountain regions, pine bark beetles (Dendroctonus spp.) have affected tens of millions of acres of forest, disrupting complex ecosystems that provide a wide range of goods and services. This study focuses on the extraction and characterization of phytochemicals from selected plants to explore their potential application as natural biopesticides against pine bark beetles threatening North American pine forests. Knowledge of certain plants and herbs that possess a large collection of bioactive, chemically diverse compounds is imperative for developing alternative pest management strategies. Several indigenous tropical plants, including Boerhavia diffusa (MU1), Euphorbia hirta (AOU), Scoparia dulcis (AU1), and neem (Azadirachta indica), were subjected to aqueous and solvent extraction. Initial phytochemical screening indicated that ethanolic extracts of MU1, AU1, and AOU exhibited greater than 35% inhibition compared to the control (ascorbic acid). Among the aqueous extracts, AOU demonstrated the highest DPPH scavenging activity at the lowest concentration tested (0.03125 mg/mL). Bacterial and fungal activity studies are ongoing and aim to elucidate mechanisms by which these phytochemicals may disrupt the mutualistic relationship between bark beetles and their associated fungi, thereby reducing beetle survival and infestation rates.