Transmission of Theileria Annulata (Dschunkowsky & Luhs, 1904) by Hyalomma Excavatum (Koch, 1844)

Theileria annulata was transmitted transtadially by an Israeli strain of Hyalomma excavatum from larvae to nymphs and from nymphs to adults. However, the adults developing from larvae which engorged on infected calves and fed during the nymphal stage on non-infected calves, rabbits or gerbils (Meriones tristrami), did not transmit theileriosis. Suspensions of infected unfed nymphs or adults did not produce theileriosis but both nymphs and adults of the same batch became infective to cattle after 2 days of feeding. Suspensions of salivary glands or of whole ticks derived from infected adults that remained attached to rabbits for more than 7 days, were not infective to cattle.