Efeito "in vitro e in vivo" de nematóides entomopatogênicos (Rhabditida) sobre o carrapato dos bovinos Rhipicephalus (Boophilus) microplus (Acari: Ixodidae)

Abstract

Ticks are susceptible to infection by entomophatogenic nematodes (EPNs) and several works have presented ticks´susceptibility results to infection by EPNs. However, those studies are not standardized concerning ticks´ species, their evolutive stage, EPNs´ species and strains and period of time of ticks´ exposure to EPNs. The goal of this work was to increase the knowledge necessary to enable the use of EPNs in the biological control of cattle tick by in vitro and in vivo,evaluating different times of in vitro infection by the EPN Steinernema glaseri strain CCA in engorged Rhipicephalus microplus females and evaluating in vitro infection of engorged R. microplus females by the EPNs S. glaseri strain CCA and Heterorhabditis baujardi strain LPP7using the tick´s biological parameter analysis. The results showed that a 2-hour-period of exposure was enough to have engorged R. microplus females infected by the EPN S. glaseri CCA and a minimum of 24 hours of exposure was necessary in order to have an infection of engorged R. microplus females by S. glaseri CCA able to promote more than 90% of treatment effectiveness. Bovines infected by engorged R. microplus females were sprinkled using a solution of S. glaseri strain CCA and H. baujardi strain LPP7, but no effectiveness of in vivo infection of these ticks by EPNs was observed