Toxicity, behavior impairment, and repellence of essential oils from pepper-rosmarin and patchouli to termites

Plant essential oils are potential sources of insecticidal compounds, but have rarely been explored for their effect on termites. In the present study, we assessed the chemical composition of essential oils of Lippia sidoides Cham. (pepper-rosmarin; Verbenaceae) and Pogostemon cablin (Blanco) Benth. (patchouli; Lamiacaeae) and evaluated their toxicity, behavioral impairment, and repellence to termite species of the genera Amitermes and Microcerotermes (Isoptera: Termitidae: Termitinae). The main components of essential oils of L.sidoides and P.cablin were thymol (44.6%) and patchouli alcohol (36.6%), respectively. The essential oil of P.cablin was most potent against Amitermes cf. amifer Silvestri and had the lowest LD50 (0.63gmg(-1)). There was no difference in toxicity for Microcerotermes indistinctus Mathews between the essential oils of L.sidoides (LD50=1.49gmg(-1)) and P.cablin (LD50=1.67gmg(-1)). Pogostemon cablin essential oil was the most toxic to M.indistinctus (LC50=0.32lml(-1)) and A. cf. amifer (LC50=0.29lml(-1)). The essential oils analyzed exhibited high toxicity and repellence to the termites, in addition to reducing behavioral interactions among individuals, thus constituting potential termiticides.