Laboratory and field evaluation of entomogenous fungi for tick control.

Aqueous and oil-based formulations of two entomogenous fungi, Beauveria bassiana and Metarhizium anisopliae were tested for their efficacy against the three major species of African ticks; namely, Amblyomma variegatum, Rhipicephalus apendiculatus, and Boophilus decoloratus. Both fungal species and formulations were observed to induce high mortalities, especially in the larvae. The oil-based formulation was found to be more effective than the aqueous formulation. Monthly application of aqueous formulations of B. bassiana and M. anisopliae on vegitation in paddocks significantly reduced numbers of the tick R. appendiculatus on cattle. Possibilities for using entomogenous fungi in tick control, alone, or in combination with the conventional acaricides are discussed.