Potential of Entomopathogenic Fungi for the Biocontrol of Tick Populations.

Background: Ticks are significant vectors of various pathogens affecting humans and livestock, necessitating effective control strategies. The widespread use of chemical acaricides has led to resistance development and environmental concerns, highlighting the need for sustainable alternatives. Entomopathogenic fungi (EPF), particularly Metarhizium anisopliae and Beauveria bassiana, have emerged as promising biocontrol agents due to their pathogenicity against arthropods. This study evaluates the efficacy of these fungi in controlling tick populations under laboratory and field conditions. Methods: Fungal isolates of M. anisopliae and B. bassiana were cultured and applied to adult and nymphal ticks using direct immersion and topical application methods. Tick mortality was monitored over 14 days, and lethal time 50% (LT₅₀) and lethal concentration 50% (LC₅₀) values were determined using probit analysis. Environmental stability assays assessed conidial viability under different temperature and ultraviolet (UV) exposure conditions. A field trial was conducted to evaluate fungal efficacy in reducing tick populations in a natural setting. Results: Both M. anisopliae and B. bassiana induced significant mortality in ticks, with M. anisopliae exhibiting slightly higher virulence. LT₅₀ values were 5.8 ± 0.4 days for M. anisopliae and 6.9 ± 0.5 days for B. bassiana. Conidial viability declined under high temperatures and prolonged UV exposure, but fungal application in shaded areas improved efficacy. The field trial showed a 67.3% reduction in tick populations after fungal treatment (p < 0.001). Discussion: These findings demonstrate the potential of EPF as effective biocontrol agents for tick management. While environmental factors influence fungal persistence, protective formulations and targeted application strategies could enhance field performance. Integrating EPF with other control measures may provide a sustainable approach to tick population suppression.