deer tick

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun Either of two North American ticks (Ixodes scapularis or I. pacificus) that are parasitic on deer and other animals and transmit the infectious agents of certain febrile diseases, such as Lyme disease.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A hard-bodied tick of the scientific name Ixodes scapularis of the eastern and northern Midwestern United States.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a northeastern tick now recognized as same species as Ixodes scapularis