02212naa a2200325 a 450000100080000000500110000800800410001902400270006010000170008724501230010426000090022752012230023665000250145965000310148465000330151565000130154865000260156165000200158765000220160765000290162970000230165870000170168170000210169870000170171970000190173670000170175570000130177270000260178577300750181121055322019-12-27       2019    bl uuuu     u00u1 u    #d7 a10.1111/mve.123302DOI1 aBRITO, L. G.  aPyrethroid and organophosphate pesticide resistance in field populations of horn fly in Brazil.h[electronic resource]  c2019  aPesticides are used worldwide to control arthropod parasites in cattle herds. The indiscriminate and/or inappropriate use of pesticides without veterinary guidance is a reality in several countries of South America. Improper pesticide use increases the chances of contamination of food and the environment with chemical pesticides and their metabolites. Reduction of these contamination events is an increasing challenge for those involved in livestock production. The horn fly, Haematobia irritans (Linnaeus) (Diptera: Muscidae), is one of the most economically important parasites affecting cattle herds around the world. As such, horn fly control efforts are often required to promote the best productive performance of herds. Pesticide susceptibility bioassays revealed that pyrethroid resistance was widespread and reached high levels in horn fly populations in the Brazilian state of Rondônia. The knockdown resistance (kdr) sodium channel gene mutation was detected in all horn fly populations studied (n = 48), and the super kdr sodium channel gene mutation was found in all homozygous resistant kdr individuals (n = 204). Organophosphate resistance was not identified in any of the fly populations evaluated.  aAcetylcholinesterase  aHaematobia irritans exigua  aHaematobia irritans irritans  aMutation  aResistance mechanisms  aSodium channels  aMosca dos Chifres  aResistência a Pesticida1 aBARBIERI, F. da S.1 aROCHA, R. B.1 aSANTOS, A. P. L.1 aSILVA, R. R.1 aRIBEIRO, E. S.1 aGUERRERO, F.1 aFOIL, L.1 aOLIVEIRA, M. C. de S.  tMedical and Veterinary Entomologygv. 33, n. 1, p. 121-130, Mar. 2019.