Affiliation:
1. Instituto Biológico, Brasil
2. Embrapa Amazônia Oriental, Brazil
3. Polo Regional Vale do Paraíba. APTA, Brasil
Abstract
ABSTRACT Rhipicephalus (Boophilus) microplus is one of the parasites that has an impact on livestock farming in Brazil. Bioassays using the larval packet test (LPT) impregnated with cypermethrin and diazinon at different concentrations were performed to characterize phenotypic resistance (resistance level, RL), molecular resistance (mutation in domain III - S6 T2134A) and enzymatic metabolism of diazinon and cypermethrin in some populations of R. microplus that were collected in different regions of the state of São Paulo. Among the 40 farms analyzed, 18 of them presented resistance factors for cypermethrin, with RL I (53%) and RL II (47%). Mutation of domain III T2134A was found for the first time in Brazil, on seven farms. Heterozygous larvae were found on six of them and resistant homozygous larvae on four. No differences (p>0.05) in enzymatic activity of α-esterase and β-esterase were found in tests with live and dead larvae at a cypermethrin concentration of 409.6μg/cm2. Ninety percent of the farms showed resistance to the active agent diazinon: RL I in 6%, RL II in 30% and RL III in 64%. There were significant differences (p<0.05) in enzymatic activity at the highest concentration (3.2μg/cm2).
Reference27 articles.
1. P. Acaricide resistance of Rhipicephalus (Boophilus) microplus in State of Mato Grosso do Sul, Brazil;ANDREOTTI R.;Rev. Bras. Parasitol. Vet.,2011
2. In vitro evaluation of the action of acaricides on Rhipicephalus (Boophilus) microplus Canestrini, 1887 (acari: ixodidae) of dairy cattle in the municipality of Itamaraju, Bahia, Brazil;ALBUQUERQUE G.R.;Brazilian Animal Science,2010
3. Molecular quantitative assay for esterase-mediated organophosphate resistance in Rhipicephalus microplus;BRITO L.G.;Ticks Tick Borne Dis.,2017
4. Role of metabolic enzymes in conferring resistance to synthetic pyrethroids, organophosphates, and phenylpyrazole compounds in Rhipicephalus microplus;CHIGURE G.M.;Int. J. Acarol.,2017
5. Quantitative pcr detection of cholinesterase and carboxylesterase expression levels in acaricide resistant Rhipicephalus (boophilus) microplus;COSSÍO-BAYUGAR R.;J. entomol.,2009