Evaluation of mosquito larvicidal potency of leaf and fruit extracts of Olax scandens Roxb. against the vectors of dengue and lymphatic filariasis

Abstract

The emergence of resistance in insect vectors and destabilization of the ecosystem by excessive use of synthetic insecticides suggest an environmentally familiar alternative to suppress vector-borne diseases. Nowadays, phytochemicals play a major role in the biocontrol of vector populations. The present work evaluated the mosquito larvicidal potential of leaf and fruit extracts of Olax scandens Roxb. against the 3rd instar larvae of Aedes albopictus and Culex quinquefasciatus. The result of this assay indicated that the LC50 values of crude extracts of leaf and fruit 72 h post-exposure against Aedes albopictus larvae are 0.496%, and 0.879% respectively. While, LC50 values of leaf and fruit crude extracts against Culex quinquefasciatus are 0.354%, and 0.572% respectively in 72 h of exposure. Both extracts were able to create adverse effects in both the mosquito species and gave satisfactory mortality. Regarding the effectiveness of Olax scandens, the experiment reveals larvicidal toxicity of fruit extract is higher than the leaf extract and toxicity against the larvae of Culex quinquefasciatus is higher than the larvae of Aedes albopictus. The plant, Olax scandens can be used as a potent, plant-derived, eco-friendly, broad-spectrum mosquitocidal agent and it may become an important tool in mosquito management programs.