Abstract:
Two batches of unfed Rhipicephalus simus nymphae carrying Anaplasma marginale were incubated for 72h and 96h respectively at 37°C. Fifty ticks were triturated at a time and the homogenates were used to infect susceptible cattle. Others were prefed on a bovine host for 72h before tick suspensions were prepared. The same procedure was followed, using a single batch of infected adult ticks.
Incubation had no effect on the infectivity of the nymphal homogenates, but prefeeding of nymphae reduced the prepatent period by 8 days in l of the 2 attempts. In the case of the adult ticks both incubation and prefeeding reduced prepatent periods by 5 and 8 days respectively.