Phytochemical Screening and Larvicidal Assessment of Bellyache Bush (<i>Jatropha gossypiifolia</i>) Leaf Extracts Against <i>Culex quinquefasciatus</i> Larvae

Abstract

The development of resistance by Culex mosquitoes to synthetic insecticides has necessitated the continued search for alternative ones from plants. This study screened the preliminary qualitative phytochemicals and assessed the larvicidal efficacy of extracts of J. gossypiifolia leaf against third and fourth stage Culex quinquefasciatus larvae. The J. gossypiifolia was screened for the presence of phytochemicals using standard methods. After twenty-four (24) hours post exposure of both third and fourth stage C. quinquefasciatus larvae against different concentrations, (2.0mg/ml, 4.0mg/ml, 6.0mg/ml, 8.0mg/ml and 10 mg/ml) of various extracts. It showed that larval mortality increases significantly (p<0.05) with increase in extracts concentration. Acetone leaf extract showed highest mortality at 10mg/ml with 85% third stage Culex larvae mortality, followed by ethanolic leaf extract. However, least mortality was observed in n-Hexane leaf extract with 15% larval mortality against fourth stage Culex larvae. Low LC and LC values (3.715mg/ml and 12.490mg/ml) were noticed in 50 90 acetone leaf extract of J. gossypiifolia. The study observed that the highest LC and LC values (9.104mg/ml and 50 90 22.877mg/ml) were noticed in hexane leaf extracts. Conclusively, acetone leaf extract of J. gossypiifolia can be harnessed to control Culex larvae. However, there is a need to ascertain the quantities of bioactive components of J. gossypiifolia and its toxicity to non-target organisms.

Keywords: Jatropha gossypiifolia, Phytochemicals, Culex larvae