Toxicity of Mexican native plant extracts against larvae of Aedes aegypti (Diptera: Culicidae)

ABSTRACTObjectiveTo evaluate five indigenous Mexican plants [Hippocratea excelsa, Hippocratea celastroides, Argemone mexicana (A. mexicana), Tagetes lucida, and Pseudosmodingium perniciosum (P. perniciosum)] toxicity against the fourth instar larvae of the dengue primary vector, Aedes aegypti (A. aegypti).MethodsEach plant part was treated successively with hexane, ethyl acetate, acetone, and methanol to extract potential active components of the plants against the dengue vector.ResultsThere was a range of toxicity at 24 or 48 h post-exposure for the different plant parts and organic solvent used (LC50 values ranged between 20 and 890 μg/mL). Extracts from seeds of A. mexicana (hexane washing with methanol and acetone) and stem-bark of P. perniciosum (hexane) showed highest toxicity to Ae. aegypti larvae at 48 h post-exposure (LC50 values were 80, 50, and 20 μg/mL, respectively), thus making them potential candidates as biolarvicides. Efforts are on-going to characterize the bioactive components of the extracts, through chromatography, for their use as biological tools for the control of the primary dengue vector.ConclusionsA. mexicana and P. perniciosum are good candidates to combat the dengue vector, Ae. aegypti, as they were highly toxic to the larvae.