Efficacy of Fruit Pulp Solvent Extracts of Cassia Fistula Linn. Against The Fourth Instar Larvae of The Mosquito Culex Quinquefasciatus Say

The efficacy of the fruit pulp extracts of Cassia fistula Linn (Caesalpiniodae: Leguminosae) extracted with three solvents (viz. water, acetone and n- hexanes) was studied against the 4th instar larvae of Culex quinquefasciatus Say (Diptera: Culicidae) in the laboratory. Larval mortality was observed after 36 hours. The sun-dried extracts showed 18.67, 30.67, 41.33, 54.67 and 70.67 percent larval mortalities, respectively while the shade-dried extracts showed 6.67, 21.33, 42.67, 68.00 and 90.67 percent larval mortalities, respectively. The acetone based sun five extracts showed 18.67, 41.33, 60.00, 82.67 and 98.67 percent larval mortalities, respectively and the shade-dried extracts showed 17.33, 41.33, 73.33, 89.33 and 97.33 percent larval mortalities, respectively. The n-hexane based sun-dried extracts showed 21.33, 41.33, 59.67, 74.67 and 93.33 larval mortalities, respectively and the shade-dried extracts showed 33.33, 60.00, 68.00, 77.33 and 97.33 percent larval mortalities, respectively. The LC50 values for n-hexane, acetone and water based sun-dried extracts were 1.087, 1.097 and 3.211 mg/ml, respectively and the shade-dried extracts were 0.808, 1.054 and 3.048 mg/ml, respectively. No mortality was observed in control treatment. Asiat. Soc. Bangladesh, Sci. 43(1): 1-9, June 2017