Host associations and seasonal abundance of immature Ixodes persulcatus (Acari: Ixodidae) in a Lyme-disease-endemic area in China.

Ticks of nine small mammal species were studied in an area of endemic Lyme disease in Hailin County, Heilongjiang Province, from 1 May to 10 October 1986. The bulk (93%) total small mammal captures were Apodemus speciosus (45%), Clethrionomys rufocanus (31%), A. agrarius (11%) and Eutamias sibiricus; (5%): these host species accounted for 97% of the 162 ticks collected. Ixodes persulcatus Schulze were most abundant on E. sibiricus (0.64 larvae and 0.08 nymphs/squirrel), and less abundant on A. agrarius (1.16 larvae/mouse), A. speciosus (0.38 larvae/mouse) and C. rufocanus (0.37 larvae and nymphs/vole). The seasonal abundance pattern of larval I. persulcatus on four small mammal species appears as a bimodal peak (June and September), but nymphal I. persulcatus has a monomodal peak during spring. The prevalence of immature I. persulcatus on four small mammal species may play an important role in the epidemiology of Lyme disease in Hailin County.