In vitro study of the resistance of Boophilus microplusto acaricides on dairy cattle production from north region of Parana state

Abstract

From twenty five farms located in the north region of Parana state, Brazil, samples of Boophilus microplus engorged females were collected directly from naturally infested cattle and submitted to in vitro tests to verify their susceptibility to acaricides organophosphorous (triclorfon + coumaphos), amidine (amitraz) and pyretroids (deltamethina), acaricides commonly used by breeders to control Boophilus microplus were evaluated. From the data obtained in this work, it was verified that deltamethrina, amitraz and triclorfon + coumaphos have an action over engorged females mortality of 52,8%, 72,4% and 43,6 respectively. On the test of egg eclosion in percentage, deltamethrina presented 17,6%, amitraz 1,8% and triclorfon + coumaphos 15,24%. As the efficacy of the product, the results were deltamethrina 74,58%, amitraz 93,51 % and triclorfon + coumaphos 82,84%.