Tick fauna associated with sika deer density in the Shimane Peninsula, Honshu, Japan

Abstract

The tick fauna in the Misen mountains, an endemic area of Japanese spotted fever, and surrounding areas of Shimane Prefecture, Western Honshu, Japan was surveyed. A total of 7,497 ixodid ticks were collected by flagging in the Misen mountains and surrounding areas. They were classified as four genera and 12 species: Amblyomma testudinarium, Dermacentor taiwanensis, Haemaphysalis cornigera, H. flava, H. formosensis, H. hystricis, H. kitaokai, H. longicornis, H. megaspinosa, Ixodes nipponensis, I. ovatus, and I. turdus. Haemaphysalis kitaokai and H. longicornis were the dominant tick species in the Misen mountains from December to April and from May to August, respectively. Furthermore, the relative abundance of H. kitaokai and H. longicornis were negatively correlated with distance from the Misen mountains. A total of 819 ixodid ticks were collected from sika deer, Cervus nippon, hunted in the Misen mountains because sika deer activity is intensive in the mountains. They were classified as two genera and four species: H. longicornis, H. megaspinosa, L ovatus and I tanuki. Of these, H. longicornis occupied 87.6% of the ticks collected from sika deer from April to June. These results suggest sika deer are important hosts of H. longicornis in the mountains. Moreover, it is highly possible that the focal accumulation of H. longicornis in the mountains is dependent on deer density.