Larvicidal activity of robusta coffee (Coffea canephora Linn.) leaf extracts against Aedes aegypti / by Florilen R. Digma.

Research Study (Science High School) Cavite State University

Includes bibliographical references.

Science High School, College of Education (CED)

DIGMA, FLORILEN R., MOJICA, JANELLE MARIE C., and SALVACION, AUSTIN BENEDICT G., Larvicidal Activity of Robusta Coffee (Coffea canephora Linn.) Leaf Extracts Against Aedes aegypti. Research Study (General Science Curriculum). Science High School. College of Education. Cavite State University. Indang, Cavite. April 2016. Adviser: Prof. Jonathan R. Digma.

The study was conducted to determine the larvicidal activity of robusta coffee leaf extract against Aedes aegypti. The purposes of the study were to: 1) determine the phytochemicals present in the different crude extracts of robusta coffee (Coffea canephora Linn.) leaf; 2) determine the larvicidal activity of robusta coflee (Coffea canephora Linn.) leaf crude extracts against Aedes aegypti using different solvents, concentration, and exposure time; and 3) ascertain the significant difference among and between the different plant extract and concentration in terms of Jarval mortality at 24 hr., 48 hr.,-and 72 hr. of post exposure.

The processes involved in the study were the collection of coffee leaves, phytochemical screening, and larvicidal bioassay. The leaves were gathered from the robusta coffee trees in Barangay Bancod, Indang, Cavite and were air-dried for three weeks or until the leaves became crispy. The dried leaves were grinded with a mechanical blender and were soaked in aqueous, ethanol, and ethyl acetate for three days and then filtered. The solvent from the filtrate was removed by allowing it to evaporate in the fume hood. The resulting extract from the three solvent was subjected to phytochemical screening and larvicidal bioassay.

Different phytochemicals were determined from the different coffee leaf extract. The aqueous leaf extract contains only tannins, the ethanol extract contains tannins,

terpenoids, and glycosides while the ethyl acetate extract contains alkaloids, flavonoids, and terpenoids. After solvent evaporation, the dried crude extract was dissolved in acetone and was used to prepare varying concentrations of 125 ppm, 250 ppm, 500 ppm, and 1000 ppm. Late 3™ instar larvae of Aedes aegypti was used for the larvicidal bioassay. Three treatments with three replicates which were repeated for three times were done to calculate the mean percentage mortality. Statistical analysis suggests that significant differences existed among and between treatments and concentration. The highest percentage mortality of 27.22 percent after 72 hours of post exposure to 1000 ppm concentration was noted in ethyl acetate extract. It was followed by 17.22 percent and 11.67 percent mortality from ethanol and aqueous extracts, respectively. It was noted that 97.22 percent mortality was recorded from the positive control, and no mortality was recorded from the negative control.

Submitted copy to the University Library. 10/11/2016 RS-761