Dinâmica sazonal do carrapato do boi em Uberlândia, MG: base para o controle estratégico no Triângulo Mineiro

Abstract

The cattle tick Rhipicephalus microplus, present throughout Brazil, is responsible for losses estimated at three billion dollars per year. The control is based on acaricides, but the frequent use has led to appearance of resistant tick populations. To overcome this drawback, for the strategic control of ticks, acaricides should be used intensely as soon as the environmental conditions become favorable to the tick after an adverse period of the year, usually cold and dry. Therefore, the knowledge about the population dynamics of ticks in each region is essential. The aim of this study was to describe the population dynamics of R. microplus in a farm in Uberlândia, Minas Gerais, Brazil. For this purpose, however, it is essential to know the population dynamics of ticks in each region of the country. In this project the population dynamics of the cattle tick in rural property in Uberlândia, Minas Gerais is described through the evaluation of the non-parasitic phase of the tick under natural conditions and tick counts in naturally infested cattle. Evaluating the non-parasitic phase over a year, it was possible to determine up to five generations of R. microplus. In the rainy season the mean incubation period was of 34.3 days, the mean larval hatching rate as high as 98.4%, and mean larval longevity of 111 days. Dry season was unfavorable to the development of the tick, and the incubation period of the eggs increased to an average of 72.3 days, mean larval hatching rate drastically reduced (1%) and mean larval longevity decreased to 23 days. Ticks counts on cattle were carried out from January 2019 to June 2020. Five peaks of tick infestation were observed in the first year and three peaks in the first half of 2020. In conclusion five generations of R. microplus occur per year in the region and the transition from the dry to the rainy season the period indicated to begin the strategic control.