Twenty horses naturally infected by Anocentor nitens were selected and their auricular pinna were submitted to four treatments: gel associated with Beauveria bassiana, gel only, B. bassiana only, and a control group. The count and the register of the total number of grown up tick females (>3mm) were performed in each auricular pinna on days 0, 1, 4, 7, 11, 14, 18, 21, 25, and 28 for the calculus of percentage of control. Twenty females from each treatment were collected and maintained in laboratory, to calculate the periods of pre-oviposition, oviposition, incubation, and hatching and mean weight of oviposition. In the group treated with the gel associated to B. bassiana, it was observed a control percentage higher than 50% from the 4º to the 25º day, such as a progressive decrease of mean weight of the ovipositions in the period from the 7º to 14º day. For the other treatments, the control percentage was kept below 20% and the oviposition weight showed no significant difference among the treatments. The control percentages, such as reductions in mean weight of oviposition, suggest that the use of gel associated with B. bassiana potentialized the virulence of the entomopathogen.
fungus; biological control; Beauveria bassiana; tick
