Insecticide susceptibility of horn flies, Haematobia irritans (Diptera: Muscidae), in the State of Mato Grosso do Sul, Brazil.
Horn flies from wild populations were collected on cattle and exposed to filter papers impregnated with cypermethrin, permethrin, or diazinon and mortality was assessed after two hours. Resistance to cypermethrin was detected in all populations, with resistance ratios (RR) ranging from 27.6 to 91.3-...
| Autores: | , , |
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| Tipo de documento: | artigo |
| Estado: | Versão publicada |
| Data de publicação: | 2007 |
| País: | Brasil |
| Recursos: | Empresa Brasileira de Pesquisa Agropecuária (Embrapa) |
| Repositório: | Repositório Institucional da EMBRAPA (Repository Open Access to Scientific Information from EMBRAPA - Alice) |
| Idioma: | inglês |
| OAI Identifier: | oai:www.alice.cnptia.embrapa.br:doc/326335 |
| Acesso em linha: | http://www.alice.cnptia.embrapa.br/alice/handle/doc/326335 |
| Access Level: | Acceso aberto |
| Palavra-chave: | Mosca-do-chifre Piretróide Mato Grosso do Sul Brasil Horn flies Pyrethroid Organophosphate Haematobia Irritans Resistência a Pesticida Sanidade Animal animal health Brazil pesticide resistance |
| Resumo: | Horn flies from wild populations were collected on cattle and exposed to filter papers impregnated with cypermethrin, permethrin, or diazinon and mortality was assessed after two hours. Resistance to cypermethrin was detected in all populations, with resistance ratios (RR) ranging from 27.6 to 91.3-fold. Permethrin bioassays provided apparently low levels of resistance (RR<5), however, resistant flies were found in 96.9% of the populations based on diagnostic concentrations. From both pyrethroid bioassays, resistance was detected in 97.4% of the populations. On the other hand, a high susceptibility to diazinon (RR d 1.1) was detected in all populations. Pyrethroid products, most cypermethrin (92.3%) and deltamethrin (66.7%), were used in all ranches controlling horn flies (97.5%). Insecticide treatments, usually incorrectly applied, were routinely delivered by manual backpack sprayers in most ranches (84.5%). This profile of insecticide use helps to explain the widespread resistance of horn flies to pyrethroids in the state as well as their high susceptibility to the organophosphate. Inadequate control practices contribute to aggravate the resistance problem and its consequences. |
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