Kinds of Tick
Tick Identification
American Dog (Wood) Tick (Dermacentor variabilis)
One of the most frequently encountered ticks in North America is the American dog tick, also sometimes known as the wood tick. The larvae and nymphs feed on small warm-blooded animals such as mice and birds. The adult American dog tick will feed on humans and medium to large mammals such as raccoons and dogs.
Unfed males and females are reddish-brown and about 3/16-inch long. Females have a large silver-colored spot behind the head and will become ½-inch long after feeding or about the size of a small grape. Males have fine silver lines on the back and do not get much larger after feeding. Males are sometimes mistaken for other species of ticks because they appear so different from the female.
Lone Star Tick (Amblyomma americanum)
Larvae, nymph, and adult Lone Stare ticks will feed on a variety of warm-blooded hosts, including people. The larva is very tiny, about the size of a grain of salt. The nymph, the most common stage found on people, is about pinhead-sized. Adults are about 1/8-inch long and brown. The adult female has a white spot in the middle of her back. Because they are so similar in size, the lone star tick is sometimes misidentified by laypersons as the blacklegged / deer tick.
Although the Lone Star tick can transmit Rocky Mountain spotted fever, the lone star tick is not as likely to transmit the disease as the American dog tick. This tick also may transmit tularemia and ehrlichiosis to humans. The lone star tick is not believed to transmit the bacteria that causes Lyme disease (Borrelia burgdorferi), but may be associated with a related bacteria species that has not been completely identified.
Blacklegged (Deer) Tick (Ixodes scapularis)
All three active stages of the blacklegged (deer) tick will feed on a variety of hosts including people. After the eggs hatch in the spring, the very tiny larvae feed primarily on white-footed mice or other small mammals. The following spring, the larvae molt into pinhead-sized, brown nymphs that will feed on mice, larger warm-blooded animals and people. In the fall, they molt into adults that feed primarily on deer, with the females laying eggs the following spring. Adults are reddish-brown and about 1/8-inch long (or about one-half the size of the more familiar female American dog tick).
These ticks are found in wooded areas along trails. The larvae and nymphs are active in the spring and early summer; adults may be active in both the spring and fall. The blacklegged (deer) tick can transmit Lyme disease and possibly ehrlichiosis to humans.
Brown Dog Tick (Kennel Tick) (Rhipicephalus sanguineus)
The brown dog tick (kennel tick) is found throughout most of the U.S. This tick feeds on dogs, but rarely bites people. Unlike the other species of ticks, its life cycle allows it to survive and develop indoors. The brown dog tick is found primarily in kennels or homes with dogs where it may be found hiding in cracks, behind radiators, under rugs and furniture, and on draperies and walls.
The adult is reddish-brown and about 1/8-inch long, and usually attaches around the ears or between the toes of a dog to feed. After feeding, a female may engorge to ½-inch long. She then drops off the dog and crawls into a hiding place where she may lay as many as 3,000 eggs. This tick is tropical in origin and does not survive in winter outdoors. The brown dog tick is not an important carrier of human disease.
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