Two 1 year-old calfswere purchased from a hematozoon-free region
in Gansu Province and raised at our laboratory in a quarantined stable.
Adult R. (B.) microplus ticks were collected from the bodies of naturally
infected cattle in the Ganzi region, Sichuan Province, southwestern
China. Unengorged adult R. (B.) microplus ticks were fed on calfs in our
laboratory and the detached ticks were collected. All off-host stages
were maintained in an incubator at 27 °C with nearly 80% relative
humidity (RH). The animal experiments were performed according to
the approved Institutional Animal Care and Use Committee guidelines.