Effects of habitat structure on the retention of Ixodes scapularis and Amblyomma americanum (Acari: Ixodidae) adults during drag sampling surveys.

The ability of Ixodes scapularis Say and Amblyomma americanum (L.) to remain on drags, once acquired, was tested in sparse and dense shrub layer vegetation. When placed on bottoms of drags, adults of both species remained attached for distances three to four times greater in sparse vegetation compared with dense vegetation. When attached to the tops of drags, the differences in retention of ticks on drags between vegetation densities were significant only for A. americanum. In dense vegetation, drags should be checked at 10-m intervals, whereas in sparse vegetation this distance can be extended to 20 m without significant loss of acquired ticks.