Evaluation of the Insecticidal and Repellent Properties of Essential Oils Extracted from Cymbopogon citratus (DC.) Stapf, Mentha piperita L. Plants and Their Combination against Glossina palpalis gambiensis (Diptera: Glossinidae), a Vector of Trypanosomes in the Laboratory

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Résumé

Tsetse flies are primarily controlled using chemical insecticides, despite their negative environmental and health impacts. Developing safer and more sus- tainable alternatives is therefore essential. This study aims to evaluate the in- secticidal and repellent activities of essential oils from Cymbopogon citratus, Mentha piperita, and their combination, against Glossina palpalis gambiensis. Insecticidal effects were assessed through tarsal contact on glass microfiber papers impregnated with the oils, while repellency was evaluated by exposing flies to essential-oil volatiles in flight tunnels. The results show that the M. piperita at 100% concentration produced the highest knock-down (48.4%) and mortality (61.3%) rates, with a significant difference compared with C. citratus (P < 0.01). In repellency assays, C. citratus resulted in the lowest activation rate (46.5%), and all essential-oil treatments significantly reduced fly activa- tion (P = 0.01). In arm-test assays, C. citratus recorded the lowest preference rate (21.7%) and differed significantly from M. piperita (P = 0.04; OR = 3.6) and from both controls (P < 0.01). Overall, the findings indicate that essential oils from C. citratus and M. piperita have promising potential and are envi- ronmentally safer alternatives to chemical insecticides for tsetse-fly control. Some studies must implement to know well the target chemicals compounds in oils.

Mots-clés

Insecticide, Repellent, Essential Oils, Glossina palpalis gambiensis