Evaluation of larvicidal activity of elephant's ear (Marcaranga tanrius), african tulip tree (Spathodea campanulata), and Japanese alnus (Alnus japonica) leaf extracts against Aedes egypti (Diptera: culicidae) / Regine C. Galve.

Thesis (Bachelor of Science in Biology) Cavite State University.

Includes bibliographical references.

College of Arts and Science (CAS), Department of Social Sciences and Humanities

GALVE, REGINE C. Evaluation of Larvicidal Activity of Elephant's Ear (Macaranga tanarius), African Tulip Tree (Spathodea campanulata), and Japanese Alnus (Alnus japonica) Leaf Extracts against Aedes aegypti (Diptera: Culicidae). Undergraduate thesis. Bachelor of Science in Biology. Cavite State University, Indang, Cavite. June 2018. Adviser Jonathan R. Digma, MSc.
This study was conducted to determine the phytochemicals present in elephant's ear (Macaranga tanarius L. Miill. Arg.), African tulip tree (Spathodea campannulata P. BeauV.), and Japanese alnus (Alnus japonica Thunb. Steud.) Leaves qualitatively; determine the larvicidal activity of three plant aqueous leaf extracts against Ae. aegypti using different concentration, and exposure time; ascertain the significant difference among the different plant extract and concentration in terms of larval mortality at 24 hours, 48 hours, and 72 hours of post exposure; determine the median lethal concentration of the extracts after 24 hours, 48 hours, and 72 hours; and evaluate the morphological structures of the dead larvae at the termination of the experiment. . Aqueous leaf extracts of the three plants were prepared by washing the fresh leaves, cutting them into smaller pieces and osterized seven hundred grams of each plant in 700 mL of distilled water using a mechanical blender. The resulting solutions from the filtered extracts were used in qualitative phytochemical screening for the preparation of various concentrations for the larvicidal bioassay.
Phytochemical screening of the aqueous extract of M. tanarius, S. campanulata and A. japonica yielded concrete results. Tannins and phenols were detected in three plant extracts. On the other hand, the aqueous extracts of M. tanarius and A. japonica showed positive result for flavonoids, while terpenoids was only shown in S. campanulata and A. japonica. Only A. japonica showed positive result for steroids and proteins. The late third instar larvae of Ae. aegypti were used. Six treatments with three replicates which were repeated three times were done to calculate the mean percentage mortality. Statistical analysis showed that mean larval mortality after 24 hours between control as compared to the larval mortality at 100% concentration in S. campanulata and plant used exhibited significant differences (P>0.01). The median lethal concentration LC50 of M. tanarius (35.9%, 10.54% and 1.267%) after 72 hours of exposure was observed to be more potent than the median lethal concentration of g campanulata and A. japonica. The highest percentage mortality of 97.50 percent after 72 hours of post exposure to 100% concentration was also seen in M. tanarius. Morphological changes or aberrations were examined and noted in the internal structure of anal papillae of dead Ae. aegypti larvae, showing shrinkage and folded membrane as compared to the control group.

Submitted to the University Library December 05, 2018 T-7728