Larvicidal activity of essential oils from pericarps of ripe Citrus fruits cultivated in Cameroon on pyrethroids sensitive and resistant strains of Anopheles gambiae Giles, 1902

Essential oils of pericarps of ripe fruits from Citrus aurantifolia, C. limon, C. sinensis and C. reticulata were analyzed and their effectiveness assessed. Pericarps of C. sinensis (0.8%) had higher essential oil content than that of other species, mostly monoterpenes (83.60 to 97.29%). The major compound was limonene (46.84%, 76.14%, 91.43% and 94.92%, respectively for C. aurantifolia, C. reticulata, C. limon and C. sinensis). These volatile oils induced 100% mortality of larval stages of An. Gambiae strains at 400 ppm after 12 hours of exposure, except for C. aurantifolia. Volatile oil from C. limon is the most effective (LC50 = 13.75 ppm and LC95 = 54.94 ppm for the susceptible strain; LC50= 32.28 and LC95 = 104.7 for the resistant strain). Probably because of higher proportions of limonene or synergistic action of certain minor compounds. Pericarps of C. limon ripe fruit could be recommended for the development of natural biocides.