Data/hora: 02/06/2024 11:34:16

Provedor de dados: | 45
País: | Brazil
Título: | Toxicological effects and resistance to pyrethroids in Boophilus microplus from Goiás, Brazil
Autores: | Fernandes,F.F.
Data: | 2001-10-01
Ano: | 2001
Palavras-chave: | Ixodidae; Boophilus microplus; Tick control; Pyrethroid; Acaricide resistance.
Resumo: | In order to monitor the susceptibility of Boophilus microplus to acaricides and improve control measures, the effects of cypermethrin, deltamethrin and permethrin on larvae obtained in the city of Goiânia in the Brazilian state of Goiás were studied. Although these pyrethroids are already sold as acaricides, their cost-benefit efficiency has been questioned. Fasting 14-21 day-old larvae were immersed in solutions of the acaricides under test, maintained at 27±1° C, and relative humidity over 80%, and observed under the stereoscope within an apparatus originally designed for studying the non-parasitic phase of the tick life cycle. The observed toxicological effects were: excitability, repetitive motion, decreased motor ability, detachment, paralysis, knock-down and cuticular proliferation of liquids and gases. The materials used in the manufacture of this apparatus consisted of disposable Petri dishes, "organza" cloth and paraffin, none of which are toxic to tick larvae. Mean death rates after 24h were 76.3%, 87.5%, 77.6%, 91.2%, 86.2% and 100% for 25 and 50ppm deltamethrin, 150 and 300ppm cypermethrin and 1250 and 2500ppm permethrin, respectively. The ticks were resistant to commercial concentrations of deltamethrin and cypermethrin. Only 2500ppm permethrin produced the mortality recommended by the Brazilian Ministry of Agriculture.
Tipo: | Info:eu-repo/semantics/article
Idioma: | Inglês
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-09352001000500004
Editor: | Universidade Federal de Minas Gerais, Escola de Veterinária
Relação: | 10.1590/S0102-09352001000500004
Formato: | text/html
Fonte: | Arquivo Brasileiro de Medicina Veterinária e Zootecnia  v.53 n.5 2001
Fonte: | info:eu-repo/semantics/openAccess