Lois Danielle B. Banasig, Pamela Victoria R. Galang, Philline Marie B. Lopez (March 2012)
Philippine Science High School Western Visayas Campus – Department of Science and Technology (DOST-PSHS WVC), Brgy. Bito-on, Jaro, Iloilo City 5000, Philippines
ABSTRACT
For the main reason of helping minimize the number of dengue patients in the tropics, the researchers studied the larvicidal activities of Citrus sinensis essential oil from Citrus sinensis peels. Essential oil solutions of different concentrations (100, 250, 500 ppm) were tested against the larvae of Aedes aegypti. Glycerol was used as the emulsifier. 0.012% of glycerol was used in the control group. Twenty-five larvae were treated in 25mL of each concentration, of three replicates each for 24hours. Dead larvae were manually counted every 1 minute for 5 minutes, every 10 minutes for 1 hour and for 24 hours and mortality rate was then calculated. Lethal concentrations 50 and 90 were solved using the Probit Analysis. The results showed an increasing trend in terms of percent mortality. Exposure for 24-hours showed 94.67%, 97.33% and 100% mortality for 100ppm, 250ppm and 500ppm concentrations respectively, while exposure for 60-minutes showed 42.67%, 53.33% and 61.33% mortality for the said concentrations respectively. The LC50 and LC90 values for the 24-hour exposure were 35.48ppm and 173.78ppm respectively, while the LC50 and LC90 values for the 60-minute exposure were 84.14ppm and 907.06ppm respectively. These results suggest that the essential oil of Citrus sinensis is an effective larvicide against Aedes aegypti.