Mark and recapture of adult Ixodes pacificus (Acari: Ixodidae) to determine the effect of repeated removal sampling on tick abundance.

The effect of biweekly flagging on adult Ixodes pacificus Cooley & Kohls abundance was determined by using mark-recapture techniques. Ticks were recaptured up to three times during the 12-wk study, and increasingly higher proportions of marked ticks were recaptured as the study progressed. By week 6 of the study, 46% of the collected ticks had been marked, and on the final sampling date, all ticks had been captured previously. Removal sampling would have substantially reduced estimates of the abundance of the questing I. pacificus adult population. For ecological studies that require the repeated sampling of a given habitat, the most representative data are obtained by returning flagged ticks to their collection site.