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 vegeta tion. When placed on bottoms of drags, adults of both species remained atta ched for distances three to foul times greater in sparse vegetation compare d with dense vegetation. When attached to the tops of drags, the difference s in retention of ticks on drags between vegetation densities were signific ant only for A. americanum. In dense vegetation, drags should. be checked a t 10-m intervals, whereas in sparse vegetation this distance can be extende d to 20 m without significant loss of acquired ticks.