Deer ticks & maybe..
The most common carriers of borrelia burgdorferi, the bacteria
that causes lyme disease
, are deer ticks (ixodes scapularis) and their cousin ixodes pacificus (western black-legged tick).
There is evidence lone star ticks may transmit it. Other ixodes species may carry it too, as may dog ticks and rocky mountain wood ticks. See http://www.Canlyme.Com/ticks.Html for more info on this.