A Case Study of Nymphal Tick Haemaphysalis longicornis Neumann, 1901 (Acarina: Ixodidae) Infestation Found in Okayama, Japan

A case of nymphal tick infestation in 62-year-old Japanese male in Tamano City, Okayama Prefecture is reported. April 5th, 1990, infested 2 hard ticks were found on the skin surface of the left posterior upper femoral and the other tick was noticed on right posterior antebrachial region of the patient. The removed ticks were almost same in size, and bodies measured about 1.6 mm in length (including capitulum) and 1.0 mm in maximum width. Each of the ticks had 4 pairs of legs with no genital apertures. By the acarological observation, the ticks were identified as Haemaphysalis longicornis Neumann, 1901 at nymphal stage based on morphology of capitulum, coxae, internal and external spurs and spiracular plates. The patient was believed to be infested by nymphal ticks at bamboo bush near by his residence 3 days prior to visit hospital. To our best knowledge, this report is the 11th case of human infestation with hard ticks in Okayama Prefecture