Repellent and toxic effects of indigenous plant seed extracts on fungus-growing subterranean termites (Blattodea: Termitidae)

Abstract

The indiscriminate use of synthetic pesticides to control fungus-growing termites has led to biological and environmental hazards and has contributed to the development of resistance in these pests. In the search for environmentally safe alternatives, plant-derived biopesticides have been explored as replacements for synthetic insecticides. The present study aims to shed light on the use of naturally occurring anti-termite compounds extracted from the seeds of indigenous plants. Specifically, seed extracts from Moringa oleifera (sohanjna) and Citrullus colocynthis (bitter apple) were tested using methanol and water as solvents in bioassays against fungus-growing subterranean termites. The entomotoxic properties of the methanolic and aqueous extracts from these plant seeds were examined to determine their effects on termite mortality, repellency, and foraging behavior. The results revealed that both plant seed extracts negatively impacted the survival and repellency of termites. C. colocynthis showed better results in terms of termite mortality and had lower LT50 values compared to M. oleifera. However, in terms of tunneling behavior, M. oleifera) showed more significant effects than C. colocynthis. Based on the outcomes of these trials, both C. colocynthis and M. oleifera demonstrated significant potential as effective termiticides. Therefore, it is recommended that these native plant seed extracts be incorporated into termite control strategies.