Publications scientifiques
Lame Younoussa* (Auteur correspondant)
Farida Lacmago Longmou
Aurelie Dadji Foko
Kary Mallam Oumarou
Mamat Amina
Katamssadan Haman Tofel
Charles Okechukwu Esimone
Elias Nchiwan Nukenine
International Journal of Zoology
Mosquito vector elimination using botanicals is recommended nowadays because they are biodegradable and less harmful to humans and nontarget organisms. In this context, binary combinations of Citrus sinensis and Callistemon rigidus essential oils were assayed against the larvae and adults of Anopheles gambiae in the laboratory. Essential oil combinations were emulsified with Tween‐80, and concentrations of 200, 100, 50, and 25 mg/L were prepared in 100 mL with tap water. In each concentration test solution or control, 25 fourth‐instar larvae of An. gambiae were transferred, and larval mortality was recorded after 24h. Adulticidal test was conducted using CDC bottles coated with the essential oil combination at concentrations of 100, 50, 25, and 12.5 mg/L. The knockdown effect was recorded every 10 min until 1h, and adult mortality of An. gambiae adults was registered after 24 h. GC/MS analysis revealed limonene (90.07%) and 1,8‐cineole (63.30%) as the major compounds in Ci. sinensis and Ca. rigidus essential oils, respectively. Among the combinations, the mixture Cs75% + Cr25% (LC 50 = 10.70 mg/L) was the most potent, presenting a synergistic action against An. gambiae larvae. On mosquito adults, the essential oil of Ca. rigidus tested alone caused more knockdown against An. gambiae adults (knockdown concentration 50% [KdC 50 ] = 1.88 mg/L) in short time (knockdown time 50% [KdT 50 ] = 1.99 min) than the combination products. After 24 h postexposure, all the combinations presented synergistic action, and the combination Cs50% + Cr50% (LC 50 = 1.38 mg/L) was the most effective against An. gambiae adults. Thus, combinations Cs75% + Cr25%, Cr100%, and Cs50% + Cr50% could be the new phyto‐insecticide candidates to control An. gambiae larvae and adults.
