Larvicidal efficacy of the leaf and flower extracts of Tropaeolum majus L. (Tropaeolaceae) against the vector of lymphatic filariasis

Abstract

Billions of people face consequences throughout the world due to vector-borne diseases. Effective management of vector populations can reduce the burden of vector-borne diseases. The present study was conducted to assess the efficiency of Tropaeolum majus leaf and flower extracts on the Lymphatic Filariasis vector Culex quinquefasciatus. Crude extract of T. majus leaves and flowers was used for larvicidal bioassay against 3rd instar larvae. The effect of both the extracts on non-target organisms was also assessed. Log probit, regression, and ANOVA were carried out to find out the statistical significance. Crude extract of both leaf and flower showed significant larval mortality. 100% and 96% mortality were achieved within 72 h in 2% crude extracts of leaf and flower respectively. After 72 h treatment LC50 value was assessed as 0.56% and 0.78% in the case of leaf and flower extracts respectively, which were quite acceptable. ANOVA analysis established a significant relationship between exposure time and concentration of extracts in imposing mortality to the mosquito larvae. Though, the tests on the non-target organisms showed that those extracts were generally safe. The outcomes suggest that the extracts of T. majus leaves and flowers can be used as an eco-friendly mosquito larvicidal agent. The isolated compounds from this plant may also act as a potent larvicide and are worth further study.