The Brown Dog Tick, American Dog Tick, Rocky Mountain Wood Tick and the Groundhog Tick are all in a group know as hard ticks. For soft ticks, go to the Soft Tick information page. For elimination of these pests on pets, in homes and other buildings, go to the Tick Elimination page.
Brown Dog Tick Rhipecephalus sanguineus
This is one of the most widely distributed ticks on the world and there are records of its occurrence on a number of hosts. By far the most common host is the domestic dog and the brown tick is virtually restricted to this host in the United States. There are occasional collection records of people and domestic cats as hosts, but these records are generally for instances where there has been close contact with infested dogs. In other parts of the world, this tick seems to have a somewhat wider range of hosts. Under normal circumstances in North America, all feeding stages of the tick feed on dogs. The adults commonly attach to the ears and between the toes, and the larvae and nymphs are often found in hair along the back. While these developmental stages are often found on the indicated host body regions, they are not restricted to these regions and may be found on practically any part of the dog’s body.
When individuals of each feeding stage become fully engorged, they drop from the host and seek some protected situation in the immediate surroundings. For this reason, all tick life stages may be found behind baseboards, under window and door moldings, in window pulley openings or in furniture. Couple this behavior with the climbing behavior of newly hatched larvae or other stages which have not obtained a blood meal recently, and one can understand why nearly all cracks and crevices in an infested premise must be carefully treated in order to obtain good tick control. Homeowner calls usually occur in the late summer and fall when ticks are encountered crawling on carpeting, walls and sometimes furniture.
Brown dog ticks can be found outdoors in the southern United States during any time of the year, but are found outdoors during the warm months in the northern United States. It is generally believed that this species of tick cannot overwinter in the more northern United States except within a heated structure.
Adult male ticks are flat, about 1/8 inch long and uniformly re-brown with tiny pits scattered over the back. They do not enlarge upon feeding as do females Before feeding, adult female ticks resemble the males in size, shape and color. As they feed, females become engorged and swell to 1/2 inch long and 1/4 inch wide. The legs, mouthparts and shield area behind the head remain red-brown, but the enlarged portion of the body becomes gray-blue to olive. The red-brown color is distinctive and no other tick normally encountered will be uniformly red-brown.
Egg-laying begins about three days after the engorged adult female drops from the dog. She may deposit as many as 5,000 eggs in places such as between boards, under plaster or carpeting, or in other cracks and crevices. The eggs usually hatch in about three weeks, although up to several months may be required under particularly cool or dry conditions. After hatching, the larvae wait months while waiting for a host. Once on the host, the larvae feed for about three days and then drop off. Molting occurs about one week after the blood meal, and nymphs emerge to climb vegetation or vertical surfaces to again wait for a host. The second feeding will last about four days, after which they again drop off, to molt into the adult stage. Adults can live up to 1 1/2 years, without feeding, but must feed before mating. After mating, the female completely engorges herself with blood and then drops off the host to lay eggs.
A home can become heavily infested if the family dog picks up ticks from an infested residence, during which time some ticks may drop off. In this case, the home and yard may become infested even though a dog is not generally kept there. Dogs do not become infested with brown dog ticks by direct contact with other dogs. Ticks feeding on a dog drop off and molt before they will resume host-seeking behavior and attach to another dog.
American Dog Tick Dermacentor variabillis Top of Page
Dogs are the preferred host of adults of this tick species, but they will also feed readily on many other large animals. Larvae and nymphs of this species feed virtually exclusively on small, wild rodents. Newly hatched larvae are yellow with red markings near the eyes, while engorged larvae are slate-gray to black. Nymphs are similar in appearance to the larvae but have four pairs of legs instead of three pairs. Adults are generally brown, but become slate-gray when engorged.
This tick is a vector of the causal organism of Rocky Mountain spotted fever and is one of the species commonly involved with tick paralysis. This species is the most widely distributed tick of this genus in North America and is the most commonly encountered by pest management professionals. It occurs throughout the eastern and central United States.
Rocky Mountain Wood Tick Dermacentor andersoni Stiles
As its common name suggests, this species is encountered throughout the Rocky Mountain region, where it is the principal vector for Rocky Mountain spotted fever. It is commonly involved with cases of tick paralysis. Larvae and nymphs are generally found on small wild rodents, and the adults on larger mammals. However, cases are known where all three life stages have been found on medium-sized mammals such as jack rabbits. This species is a common problem for campers and other vacationers in areas within its normal range.
Groundhog Tick ixodes cokkei Packard
Both nymphs and adults of the groundhog tick may attack humans. They are most common in the New England states where they are found in summer cottages around areas frequented by groundhogs.