Fungal formulations to control Rhipicephalus sanguineus engorged females.

Entomopathogenic fungi are promising alternatives to chemical acaricides in controlling tick populations; however, biological formulations are required to improve conidial performance of these pathogens in the field. This study evaluated the effect of in vitro treatment of Rhipicephalus sanguineus with conidial formulations of Beauveria bassiana (Bb) or Metarhizium anisopliae (Ma). Conidia were formulated (at 10(8) conidia mL(-1)) in (1) emulsifiable concentrate (EC), (2) polymerized cellulose gel (PCG), or both (3) emulsifiable concentrate and polymerized cellulose gel combined (EC+PCG). Engorged females were weighed and exposed to one of six treatment groups: EC+Bb, EC+Ma, PCG+Bb, PCG+Ma, EC+PCG+Bb, EC+PCG+Ma; or to control groups: C1 (untreated) or (C2) treated with Tween 80 aqueous solution, EC or PCG. After exposure, ticks were placed in petri plates and kept at 27 +/- 1 degrees C and 80% relative humidity (RH). Ticks treated with formulated conidia of entomopathogenic fungi showed significantly higher control percentage in comparison to that of control groups. The formulation of B. bassiana with EC and PCG combined (EC+PCG+Bb) caused the highest control percentage (86.79%) of R. sanguineus. This study concludes that entomopathogenic fungus conidial formulations are important to ensure effective tick control.