The c/ossif~ cation of the benign speoes of Theileria of cattle is very confusing. Representatives of this group of pora-sites appear worldwide, and are known as T. sergenti injapan, T. b&Ii in Austraiia and T. orientalis elsewhere. Consequently, these parasites cre frequently referred to as the T. sergenti/buffeli/orientalis group. Kozo fujisaki, Shin-ich, ro Kawazu and Tsugihfko Kan; io here argue that the Australian T. buffeli and Bn’tish T. orientalis beiong to one (2nd the same species, and that the Japanese T. sergenti is a separate species.

There are many questions and controversies surrounding the classification of the Theilena sergentilbuffelilorientalis group of parasites (see Box I). The primary question is whether or not the Japanese T. sergenti can be regarded as the same species as T. buffeli and T. orientalisl. If not, Japanese Theileria should be given a diffe-ent specific name.