DOI: 10.36347/sajb.2019.v07i12.008

Pages: 503-516

The use of plant extracts and essential oils has recently been referred to as an eco-friendly alternative in insect vector control. The present study evaluated the larvicidal, adulticidal and repellent potential of extracts and essential oils of Zanthoxylum delagoense, Bridelia cathartica Bertol and Ocimum americanum against the housefly Musca domestica L. The ethanolic and aqueous extracts were obtained by Soxhlet extraction and essential oil was obtained by hydrodistillation with modified Clevenger apparatus. Phytochemical screening has been conducted on aqueous and ethanolic extracts using standard methods. Essential oils have been analyzed qualitatively by GC-MS. For biological assays, concentrations of 5000, 3000 and 1000 ppm were prepared for the extracts and 2000, 1000 and 500 ppm for the essential oils. Zanthoxylum delagoense and Ocimum americanum essential oil mixtures were made to evaluate the synergistic effect. Phytochemical screening revealed the presence of alkaloids, anthraquinones, flavonoids, steroids, triterpenoids and condensed tannins in ethanolic and aqueous extracts. 7 compounds were detected in Bridelia cathartica Bertol leaves essential oil, Phytol was the major constituent; 5 compounds were identified in Ocimum americanum essential oil, Fenchone, D-limonene and Humulene were the major compounds; 11 compounds were identified in Zanthoxylum delagoense leaves essential oil, 1-methylene-4-(1-methylethenyl) Cyclohexane, 4-methylene-1-(1-methylethyl) Bicyclo [3.1.0] hexane and β-Myrcene were the major compounds. Essential oils showed higher larvicidal, repellent and adulticidal activity than extracts. Zanthoxylum delagoense essential oil and binary oil mixtures were found to have the highest insecticidal activity against Musca domestica with 100% mortality at 24 hours exposure. Extracts and essential oils of the three plants have been found to have potential larvicidal, adulticidal and repellent activity against Musca domestica L.