[Epizootiological study of theileriasis in Korea: Prevalence of the bovine theileriasis in relation to its vector, Haemaphysalis (Kaiseriana) longicornis Neumann. 1901]
Investigations of some problems related to the bovine theileriasis and its vector have been undertaken in Korea. Owing to the nation-wide investment of dairy farming, hundreds of milk cattle were imported from foreign countries during the last l0 years. This caused some problems for the imported dairy cattle in terms of cattle piroplasmosis, from which native Korean cattle are immune. The bovine theileriasis has been studied from the beginning of the 20th centry in Korea, and the carriers and incidences of theilerial infection were reported by several authors during the past 60 years. Theilerial species in Korea is still unknown, but Han(1968) reported that it might be the same species as found in Japan. The latest work of Ishihara(1969) suggested that the species of the genus Theileria in Japanese cattle would be one similar to Theileria sergenti in Russian cattle. The tick responsible for the transmission of Korean theileriasis, Haemaphysalis (Kaiseriana) longicornis Neumann 1901 was incriminated as in the name of Haemaphysalis bispinosa (synonym) by Han(1968). The tick vector was re-examined thoroughly following the description of Hoogstraal et a1. (1969). There were no significant differences in the morphological character of ticks between Hoogstraal et al. and Jang(l973). The population fluctuation of H. longicornis in comparison with Boophilus microplus which is major important cattle tick was surveyed based on the collection of them at Suweon Stock Market through a year. The activities of the ticks begin on the central part of Korea in April and showed two highest population densities in May and July, and disappeared almost all in September.