LARVICIDAL POTENTIAL OF AMPALAYA (MOMORDICA CHARANTIA) STEM EXTRACT AGAINST MOSQUITO LARVAE

Abstract

Mosquitoes, with approximately 3,700 identified species, are vectors of diseases such as malaria, dengue, and Zika, which cause severe illnesses, particularly in tropical and subtropical regions. Dengue fever remains a persistent public health concern in the Philippines. Synthetic insecticides are commonly used to control mosquito populations; however, their excessive use has been associated with health risks, the development of mosquito resistance, and environmental damage. Consequently, there is a strong need to develop alternative insecticides and vector-control strategies to address pesticide resistance. One potential option is Ampalaya (Momordica charantia), a tropical vine known to contain biologically active compounds. Thus, this study aimed to develop a community-beneficial organic larvicide derived from Ampalaya stem extract. The efficacy of Ampalaya (Momordica charantia) stem extract against mosquito larvae was evaluated using a true experimental research design. The stems were air-dried in a shaded area for five days, powdered, soaked in ethanol for three days, filtered, and extracted using a rotary evaporator. Three concentrations of the ethanolic stem extract—50%, 75%, and 100%—were prepared. ABATE 1 SG was used as the positive control, while tap water served as the negative control. Each concentration was tested on ten early fourth-instar mosquito larvae, with three replicates per treatment. Larvicidal efficacy was assessed based on knockdown time and mortality rate. Analysis of Variance (ANOVA) was employed to determine significant differences among the concentrations. The results showed that the 100% ethanolic extract of Ampalaya stem exhibited strong larvicidal activity, with a mortality rate of 96.7% within one hour and 100% mortality at both the two- and three-hour observation periods. As the concentration decreased, larvicidal efficacy also declined. The 75% concentration resulted in an 80% mortality rate within one hour, 96.7% after two hours, and 100% after three hours. The 50% concentration produced a 33.3% mortality rate after one hour, increased to 90% after two hours, and reached 100% after three hours. The positive control achieved an 86.6% mortality rate within one hour and 100% mortality at the two- and three-hour intervals, while the negative control exhibited no larval mortality throughout the experiment. The findings suggest that the 100% ethanolic extract of Ampalaya (Momordica charantia) stem can be effectively used as a larvicide against mosquito larvae. Its efficacy was comparable to that of the commercial larvicide. However, the 75% and 50% concentrations demonstrated significantly lower effectiveness when compared to the commercial control.