Efficacy of winter–spring strategic control against Rhipicephalus (Boophilus) microplus infestations on cattle in an area with ecological conditions highly favourable for the tick in northeast Argentina

Abstract

This work was performed to test the efficacy of winter?spring controlstrategies against Rhipicephalus (Boophilus) microplus (Ixodida: Ixodidae) infestationson cattle in the area ecologically most favourable for the development of this tick inArgentina. Two control schemes using three and four annual applications of acaricides,respectively, were evaluated. Animals in Group 1 were treated with ivermectin 3.15% onday 0, fluazuron on day 34, and fipronil on day 85. Animals in Group 2 were treated withivermectin 3.15% on day 0, fluazuron on day 34, flumethrin on day 85, and fipronil onday 114. Animals in Group 3 represented the control group. Both treatment schemesprovided appropriate levels of efficacy against R. microplus and also prevented theoccurrence of the major peak in the frequency of this tick in autumn. The two treatmentschemes were similar in terms of efficacy and thus the addition of a fourth treatment doesnot seem to confer any further advantage. The results of this work indicate that thesestrategic control methods provide appropriate levels of control against R. microplus.