Evaluation and Molecular Characterization of a Native Beauveria Bassiana Isolate for the Biological Control of Rhipicephalus Microplus in Tropical Cattle Production

Rhipicephalus microplus is a tick of major veterinary relevance that causes significant economic losses in tropical cattle production due to its blood-feeding behavior and its role as a vector of hemoparasites. The extensive use of chemical acaricides has led to the development of resistant tick populations, highlighting the need for sustainable biological alternatives. Among these, entomopathogenic fungi such as Beauveria bassiana have gained attention for their efficacy against arthropod pests and low environmental impact. This study aimed to evaluate the in vitro and in situ efficacy of a native B. bassiana isolate against engorged females of R. microplus and to confirm its taxonomic identity through multilocus phylogenetic analysis. Two treatments were applied by immersing ticks in 5 mL and 10 mL of a conidial suspension (1 × 10⁸ conidia/mL), along with an untreated control group.