Termite Odontotermes obesus Herbivory Modulates Behavioural Response of Spodoptera litura by Triggering Metabolic Shifts in Groundnut Plants.

Groundnut plants subjected to root herbivory by Odontotermes obesus exhibited significant changes in the behavioural responses of Spodoptera litura, characterized by reduced oviposition rates and modified feeding preferences compared to healthy plants. Our findings provide strong evidence that groundnut plants under termite attack mobilized both metabolic and volatile defenses to mitigate further herbivory, supporting the defense induction hypothesis. The elevated levels of phenols, sugar alcohols (D-Pinitol, D-Allose, D-(+)-Xylose), and insecticidal fatty acids (9-Octadecenoic acid, 10-Undecenoic acid) demonstrate a coordinated shift in primary metabolism aimed at reducing herbivore performance. Simultaneously, the altered volatile organic compound emissions (alkanes, alkenes, tetradecane) suggest an indirect defensive strategy, potentially recruiting natural enemies or disrupting host-finding cues of S. litura. These findings demonstrate that below-ground termite herbivory induces significant metabolic shifts in plants, which in turn modulate S. litura oviposition behaviour and larval feeding preferences, highlighting a complex cross-trophic interaction between root and shoot herbivores.