REPELLENT EFFECT OF SCENT LEAF (OCIMUM GRATISSIMUM) EXTRACT AGAINST HOUSEFLY (MUSCA DOMESTICA) IN OTUOKE, OGBIA LOCAL GOVERNMENT AREA, BAYELSA STATE

This study evaluated the repellent effect of Ocimum gratissimum (scent leaf) extract against houseflies (Musca domestica) in a laboratory setting at Federal University Otuoke, Nigeria. The objectives were to extract and the bioactive compounds, assess repellent efficacy under controlled conditions, and determine the optimal concentration for repellency. Fresh scent leaf (189.7 g) was air-dried, pulverized to 27 g, and extracted with 127 ml ethanol over 72 hours. Two solutions (50%: 0.5 g extract in 45 ml water; 100%: 1 g extract in 90 ml water) were tested using crayfish bait to attract houseflies, with observations recorded at 5-minute intervals. The 50% solution reduced housefly numbers from six to one over 20 minutes, while the 100% solution eliminated housefly presence within 5 minutes, sustaining repellency for most of a 25-minute period, except for a brief reappearance of one housefly. Chi-square analysis (X2 = 5.25, p = 0.022) confirmed the 100% solution’s superior efficacy. Although direct characterization of bioactive compounds was not conducted, literature suggests eugenol and linalool as key contributors. The 100% solution was identified as optimal, achieving a 100% reduction in housefly presence compared to 83.3% for the 50% solution. Limitations include the lack of chemical analysis, short observation period, and laboratory setting. These findings highlight Ocimum gratissimum extract as a promising eco-friendly repellent, warranting further field studies and formulation optimization.