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Larvicidal Effect of Medicinal
Plants Against Aedes aegypti (L.) (Diptera: Culicidae) in Mexico
FILIBERTO REYES-VILLANUEVA1, OTHÓN J. GONZALEZ-GAONA2
& MARIO A. RODRÍGUEZ-PEREZ3
1Universidad Autónoma de Nuevo León, Facultad
de Ciencias Biológicas, Laboratorio de Entomología, Apdo.
Postal 105, San Nicolás de los Garza, Nuevo León, 66450,
México. E-mail: freyes@fcb.uanl.mx
2Instituto Tecnológico de Ciudad Victoria, Blvd..
Emilio Portes Gil 1301 Pte. Ciudad Victoria, Tamaulipas, México.
E-mail: othonjavier@hotmail.com
3Centro de Biotecnología Geonómica, Instituto
Politécnico Nacional, Blvd. Del Maestro Esquina Elías Piña,
Col. Narciso Mendoza, Reynosa, Tamaulipas, México. E-mail: drmarodriguez@hotmail.com
Enviado em: 13/III/2008 Aceito em: 26/X/2008; Publicado
em: 02/XI/2008
Efeito Larvicida de Plantas Medicinais no Controle de Aedes
aegypti (L.) (Diptera: Culicidae) no México
RESUMO - Alguns fitoquímicos apresentam compostos tóxicos
que podem ser explorados no controle de larvas de mosquitos. Sendo assim,
o efeito larvicida de extratos aquosos a 0,05% (peso:volume) de 14 plantas
medicinais foram avaliadas para o controle de larvas de Aedes aegypti
(L.)
no México. Os bioensaios foram conduzidos com larvas nos estágios
iniciais do quarto instar mediante a submersão das larvas nos extratos.
Resultados preliminares com as plantas testadas mostraram que a maior mortalidade
foi observada com extratos de macerados e de plantas inteiras. As mortalidades
médias obtidas para Solanum nigrescens
Martens & Galeotti,
Operculina
pteripes (G.Don) O'Donell e Phoradendron tamaulipensis
Trel.
foram 55; 17,5 e 5,8% respectivamente. Posteriormente, foram realizadas
bioensaios com plantas de S. nigrescens
coletadas mensalmente no
campo para avaliar o efeito sazonal na atividade larvicida com diferentes
partes da planta. Somente extratos obtidos das raízes maceradas
(mortalidade de 83 a 100%) ou inteiras (mortalidade de 88 a 98%) foram
letais às larvas de A. aegypti. As mortalidades mensais médias
obtidas com extratos de raízes maceradas ou inteiras de S. nigrescens
foram
91,6 e 93,3% respectivamente.
PALAVRAS-CHAVE - Aedes aegypti, plantas medicinais, extrato
aquoso, Solanum nigrescens.
ABSTRACT - Some phytochemicals comprise toxic compounds that
can be exploited in the control of mosquito larvae. Therefore, larvicidal
effect of aqueous extracts of 14 medicinal plants at 0.05% (weight: volume)
was evaluated against Aedes aegypti (L.) in Mexico. Bioassays were
conducted
with early fourth instars submerged in plant infusions to ingest the potential
insecticide compounds. A preliminary bioassay for all plants showed that
the highest mortality occurred in extracts from crushed and whole plants.
The mean mortality for Solanum nigrescens Martens & Galeotti,
Operculina
pteripes (G.Don) O'Donell and Phoradendron tamaulipensis
Trel.
was 55, 17.5 and 5.8% respectively. Then, monthly bioassays with fresh
field-collected S. nigrescens were conducted to evaluate seasonal variation
in larvicidal activity with different plant parts. Only extracts of crushed
(83-100% mortality) and entire (88 – 98% mortality) root were lethal to
A. aegypti larvae. Monthly average mortality was 91.6 and 93.3%
for crushed and whole root extracts of S. nigrescens. These findings
can be exploited to developed ecologically friendly products to be integrated
with other control tactics in dengue vector control program in Mexico.
KEYWORDS - Aedes aegypti, larvicidal, medicinal plants,
aqueous extract, Solanum nigrescens.
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