Autor(es): Kamalakannan, Siva; Murugan, Kadarkarai; Barnard, Donald R.

Resumo: Alternative control strategies for the dengue vector Aedes aegypti L. (Diptera: Culicidae) include botanical insecticides. They are believed to pose little threat to the environment or to human health and may provide practical substitutes for synthetic insecticides. In this study, we determined the biological activities of methanol extracts of Acalypha indica L. (Euphorbiaceae) and Achyranthes aspera L (Amaranthaceae) leaves individually and in combination as botanical insecticides against Ae. aegypti. Based on LC sub(50) values for 4th instar Ae. aegypti, the combined extracts showed the strongest larvicidal activity (277 ppm). A. aspera and A. indica extracts individually gave similar results (409 and 420 ppm, respectively). Respective LC sub(50) values for pupae were 326 ppm, 456 ppm, and 467 ppm. In studies of smoke toxicity, 64% of females exposed to negative control smoke (no extract) blood fed on chicken, whereas 17% blood fed when exposed to smoke containing A. aspera extract and to positive control smoke (0.2% d-allethrin). In the field, treatment of water storage tanks ([asymptotic to] 0.5 m super(3)) with combined plant extract reduced larval and pupal populations by 97% and 81%, respectively, after 5 days. Given the results of this study, further evaluation of the combined (A. indica + A. aspera) extract as a mosquito larvicide is warranted. Mosquito coils with A. aspera extract also show promise as a practical and potentially economical means for mitigating mosquito blood feeding.

Palavras-Chave: Larvicide; Mosquito coil; Smoke; Bioassay

Imprenta: Journal of Asia-Pacific Entomology, v. 14, n. 1, p. 41-45, 2011.

Descritores: Aedes aegypti - Larvicide ; Aedes aegypti - Dengue ; Aedes aegypti - Public health

Data de Publicação: 2011