[Effectiveness of Beauveria bassiana (Baubassil) on the common cattle tick Rhipicephalus microplus in the Department of Guajira, Colombia].

The effectiveness of Baubassil(Beauveria bassiana) on the tick Rhipicephalus (Boophilus) microplus was evaluated. In the in vitro phase, the optimal germination temperature of the fungus was determined by microcultures at 25, 30 and 35°C and the mortality of ticks. In the field, in a randomized design, 30 cebuine cows; 15 cows were treated with Baubassil once a week at a 1×10 conidia/ml, and a control group was left untreated. It was observed that at temperatures of 25, 30 and 35°C, germination of the entomopathogen was 97.5, 94.7 and 6.3%, respectively. In animals treated with Baubassil obtained a corrected effectiveness of 96.8% on ticks in the fifth week of application. The use of Baubassil would be a valid alternative for controlling the cattle tick under the agroecological conditions of the Dry Caribbean.