Effects of Andrographis paniculata Nees on growth, development and reproduction of malarial vector Anopheles stephensi Liston (Diptera: Culicidae).

The use of environment friendly and easily biodegradable natural insecticides of plant origin has received progressively more attention as insecticide alternatives for the control of medically important mosquito vectors. The ethanol and methanol extracts of Andrographis paniculata Nees were evaluated for its effects on growth, development and reproduction of malarial vector Anopheles stephensi Liston. After 8 days of treatment, 88.60 and 85.25% of the larvae treated at 35p.p.m. failed to emerge in ethanol and methanol extracts respectively. In addition, the duration of larval instars and the total development time were prolonged, while female longevity and fecundity were markedly decreased. The suppression of pupation and adult emergence was probably due to juvenile hormone analog similarities in combination with growth regulators and toxicity, which reduced the overall performance of the malaria vector An. stephensi.