An experimental analysis on the summer activity of the new generation of Haemaphysalis flava adults (Acari : Ixodidae) on vegetation

Abstract

Abstract : In order to clarify whether or not Haemaphysalis flava adults found on vegetation in the summer include a new generation, the activities of the field-collected adults in June 2001, July 2003, and October 2003 were observed in plastic cylinders that were placed outdoors. Haemaphysalis flava adults collected in June and July actively climbed the plastic cylinders immediately after they were released (June and July). However, the activities decreased sharply from the summer and were scarcely observed from the autumn to the following spring (May). Haemaphysalis flava adults collected in October actively climbed the plastic cylinders until the following spring after release (October). Since the new generation of H. flava adults is active until the following spring, these results suggest that the field-collected adults in summer do not include a new generation but those collected in autumn do. The new generation of H. flava adults appears to commence the activity in autumn.