Sensibilidade de diversas populações do carrapato Rhipicephalus microplus (ACARI: IXODIDAE) a acaricidas, em fazenda leiteira, Uberlândia, Minas Gerais

Abstract

The cattle tick, Rhipicephalus microplus, causes high economic losses to Brazilian livestock, both by blood spoliation and transmission of infectious agents. The control of the parasite is essential for cattle breeding, especially in dairy cattle taurine cattle, more susceptible to ticks. In the absence of effective alternatives, the control is done with acaricides. However, the indiscriminate use and without technical guidance led to the development of populations of ticks resistant to several active principles. For this reason, the adequate control depends on the determination of the sensitivity of the target tick populations to the various acaricides and their rational use integrated into the farm management. This project evaluated the current tick control, determined the levels of environmental infestation in the various rearing stages of dairy cattle, evaluated the sensitivity to acaricides of tick populations in each rearing stage of dairy cattle, and proposed the rational use of these in line with the management at the Glória Farm of the Federal University of Uberlândia, Minas Gerais In this first stage of the project, it was possible to map the areas destined for dairy cattle farming at Fazenda do Glória, as well as the dynamics of use of this area and management in general. Several commercial products with efficacy already compromised by the resistance of the parasite against the tick R. microplus, whereas others with 100% efficacy were observed. Unfortunately, the latter refer to products that cannot be used for actively producing cows as they have a residual effect that contaminates the milk. Among the tests to assess the efficacy of acaricides, the adult immersion test proved to be the most effective to assess the level of resistance of a tick population to acaricides.