Diagnosis of the control and efficacy of acaricides to bovine tick in the semiarid of North of Minas Gerais / Diagnóstico do controle e eficácia de acaricidas para o carrapato bovino no Semiárido do Norte de Minas Gerais

ABSTRACT

Background: Among the major ectoparasites of farm animals, Rhipicephalus microplus is the largest negative impact onthe economy of dairy farms. The spread of this mite is higher in tropical countries such as Brazil, and in cattle with predominance of taurine. The use of acaricides is most effectively used in their control, however, inadequate management hascontributed to the selection of resistant populations to products available in the market. Little is known about the controland resistance to these products for cattle in semi-arid conditions. Thus, we aimed to evaluate the management practicesused to control in dairy herds in semiarid region of northern Minas Gerais, checking the sensitivity of R. microplus todifferent acaricides.Materials, Methods & Results: A total of 62 properties located in nine municipalities in northern Minas Gerais were visited. Bocaiúva, Francisco Drumont, Francisco Sá, Icaraí de Minas, Juramento, Montes Claros, Pedras de Maria da Cruz,São Francisco and Varzelândia. The sensitivity of the ticks from cattle herds with high infestations was evaluated usingthe technique of biocarrapaticidograma. Semi-structured questionnaires were applied to characterize breeding systems,racial composition of the flock, season of greatest infestation, active ingredients used in tick control, forms of applicationof acaricides and the general management of the farm. The predominant type of exploitation was the dairy cattle representing 67.7% of the farms. The extensive system was predominant (58.06%) and crossbred...