ENHANCING MOSQUITO REPELLENCY: INVESTIGATING THE EFFICACY OF BAY LEAVES (LAURA NOBILIS) AND ORANGE PEEL OIL (CITRUS SINENSIS) IN INCENSE STICKS

Abstract

Mosquitoes are among the deadliest insects worldwide due to their role in transmitting mosquito-borne viral and parasitic diseases such as dengue, malaria, filariasis, chikungunya, and Japanese encephalitis, which continue to cause significant morbidity and mortality globally. While synthetic mosquito repellents are widely used, many contain chemical substances such as N,N-diethyl-m-toluamide (DEET), picaridin, allethrins, permethrin, and other compounds that may produce adverse side effects. This study aimed to evaluate and compare the efficacy of organic mosquito-repellent incense sticks made from bay leaves and orange peel oil with commercially available mosquito repellents and ordinary incense sticks. This study employed a true-experimental research design. A total of seventy-five (75) mosquitoes were divided into three (3) groups of twenty-five (25) each through random selection. Methanolic extracts of bay leaves (Laurus nobilis) and oil extracted from orange peel (Citrus sinensis) were used in the formulation of organic incense sticks. The net cage method was applied to test efficacy across three groups: negative control, positive control (commercial mosquito-repellent incense), and the experimental group. Effectiveness was assessed based on repellency rate, duration of repellent activity, and mortality rate. The combined extract of bay leaves and orange peel oil demonstrated a 100% repellency rate and a 60% mosquito mortality rate. In comparison, the positive control (commercial mosquito-repellent incense sticks, Mr. Dolphin Mosquito Killer) also achieved a 100% repellency rate but resulted in a lower mortality rate of 32%. Additionally, the organic incense exhibited a faster onset of repellent activity, beginning at 3 minutes and 31 seconds, whereas the commercially available product initiated repellency at 5 minutes and 6 seconds. The findings revealed a significant difference in efficacy between the organic incense made from bay leaves and orange peel oil and commercially available mosquito-repellent products. Although both achieved equal repellency rates, the organic formulation demonstrated a higher mosquito mortality rate and faster repellent action. These results indicate that the combined extracts of bay leaves and orange peel oil possess strong repellent and insecticidal properties, highlighting their potential as an effective, natural, and safer alternative to synthetic mosquito repellents.