Olfactory and Trail-Following Responses of Coptotermes curvignathus to Selected Plant Leaf Extracts

Abstract

Subterranean termites, particularly Coptotermes curvignathus, are destructive pests that cause serious damage to wood, crops, plantation commodities, and building structures. The development of plant-based semiochemicals may provide an environmentally friendly alternative for termite management by utilizing natural compounds that influence termite orientation behavior. This study aimed to evaluate the olfactory and trail-following responses of C. curvignathus workers to selected plant leaf extracts and to identify their potential roles as attractants, repellents, or trail-disrupting agents. Leaves of cajuput, eucalyptus, citronella, pine, and tea tree were extracted using 70% ethanol, concentrated by rotary evaporation, and analyzed using gas chromatography-mass spectrometry (GC-MS). Olfactory responses were tested using a Y-tube olfactometer, while trail-following behavior was evaluated using a Y-shaped filter paper assay. Each treatment was replicated 15 times using different worker termites, and the data were analyzed using the chi-square test. The highest olfactory response was observed in cajuput extract (80.00%), followed by eucalyptus (60.00%), pine (53.33%), tea tree (40.00%), and citronella (33.33%). In the trail-following assay, cajuput produced the highest positive response (93.33%), followed by pine (80.00%), eucalyptus (53.33%), tea tree (33.33%), and citronella (26.66%). GC-MS analysis showed that cajuput was dominated by α-pinene and 1,8-cineole, while citronella contained geraniol and citronellol, compounds associated with repellent activity. These findings indicate that plant-derived volatile monoterpenes influence termite orientation and trail-following behavior. This research supports SDG 12 and SDG 15 by promoting plant-based termite management and reducing reliance on synthetic termiticides.