Development of infectivity in Hyalomma detritum (Schulze, 1919) ticks infected with Theileria annulata (Dchunkowsky and Luhs, 1904).

The time-course for the development of infectivity was studied in Hyalomma detritum ticks fed as pre-imagoes on calves infected with Theileria annulata. Unfed adults derived from infected nymphs were non-infectious when inoculated into susceptible calves, whereas ticks of both sexes that had fed for 2-3 days or longer on calves or rabbits were always infectious. Some adults fed for only 1-2 days were infectious, whereas others were not. As few as 2 ticks were capable of infecting susceptible calves.