SELECTION OF ISOLATES OF ENTOMOPATHOGENIC FUNGUS FOR CONTROL OF Rhipicephalus microplus (Acari: Ixodidae)

Abstract

The aim of this study was to evaluate the in vitro susceptibility of larvae unfed of  Rhipicephalus microplus to different isolates of entomopathogenic fungi native of soil of livestock units and know the characteristics of growth and inoculum potential of isolates that showed to be more pathogenic. Pathogenicity and virulence of isolates of Metarhizium anisopliae sensu lato (Ma), Beauveria bassiana (Bb) and, Isaria fumorosea (Ifr) was evaluated in R. microplus larvae of 7 days old, exposed by immersion in an aqueous solution at concentration of 1x108 conidia / ml. Ma135 and Ma133 isolates, showed high pathogenicity with 100 and 94% mortality, with LC50 values ​​of 5.2x104 and 2.5x104 conidia / ml, respectively. In these isolates, the production of spores was 1.0x10¹º conidia / ml, and the radial mycelial growth were 3.07 and 3.60 mm / day, respectively. These results demonstrate that the isolated Ma135 and Ma133, can be considered as potential biocontrol agents in R. microplus larvae