The maintenance and survival of Theileria annulata in colonies of Hyalomma anatolicum anatolicum.

Procedures are described for the colonization of Hyalomma anatolicum anatolicum ticks using gerbils, rabbits and cattle as hosts. On rabbits H. a. anatolicum undergoes a two-host cycle but methods are described for obtaining either unfed or engorged nymphs. Data are given on the life cycle timings and the numbers and timings of tick feeding regimes. The infection of H. a. anatolicum with two strains of Theileria annulata is described and methods given for monitoring the development and survival of T. annulata in H. a. anatolicum. Data are presented indicating the optimum maintenance conditions for T. annulata in H. a. anatolicum. Piroplasm parasitaemias in cattle greater than 2% gave high infection rates in adult ticks if engorged nymphs were moulted at 28 degrees C for 28 days. The Theileria will survive for ten months in such adults stored at 12 degrees C after moult, and when fed the ticks will produce maximum numbers of sporozoites on the third day of feeding, whatever their age. The moult of engorged nymphs is retarded at 18 degrees C but the Theileria in such ticks will develop normally when the ticks are moulted at 28 degrees C after four months storage at 18 degrees C.