Vol. 2, Issue 2, Part A (2015)

Author(s): Tamilselvan Pratheeba, Chinnasamy Ragavendran and Devarajan Natarajan

Abstract: The current study was aimed to investigate larvicidal, pupicidal and adulticidal activities of acetone, hexane and chloroform extracts of Ocimum gratissimum against filariasis mosquito vector Culex quinquefasciatus Chloroform extract exhibited better mortality rate than other extracts with the LC₅₀ and LC₉₀ values of 2.8916 mg/ml and 5.4521 mg/ml at 24 hrs. The better pupal activity of mosquito was noticed in the same extract exposure at 24 hrs and the LC₅₀ and LC₉₀ values were of 2.6916 mg/ml and 4.6521 mg/ml. Adulticidal activity of extracts showed varying percentage of mortality at different time intervals. HPLC analysis showed 3 major peaks with the maximum peak area of 72% (at RT of 9.888 minutes). The GC - MS results reveals the presence of 33 compounds, out of them, 5 are identified as bioactive compounds. Major functional groups of bioactive extracts were identified by FT-IR analysis. Results suggested that O. gratissimum chloroform extract was an excellent agent for controlling filarial vector, Cx. quinquefasciatus.