Ticks

Overview:

Ticks are external parasites on mammals, birds, reptiles and on some amphibians.  There are two families of ticks; the Ixodidae (hard ticks) and the Argasidae (soft ticks).  The species we deal with most in this area are the American dog tick (hard tick), commonly known as a Wood Tick, and the Brown Dog Tick (hard tick).  These ticks occur mostly in woods and field areas.  They are generally not a household pest, but occur often in the immediate vicinity of the home.  They are annoying pests and can be vectors of disease such as Rocky Mountain Spotted Fever and Tularemia.  They commonly situate themselves along pathways where animals or hikers are likely to be attacked.   

Facts:

Ticks are not insects but are arachnids and are in the same family as spiders which means they have 8 legs (all insects have 6), however the larval stage of the tick has only 6 legs.

Identification:

AMERICAN DOG TICK
One of the most frequently encountered ticks 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.
They generally are found on grass, shrubs, brush and other vegetation, particularly along animal trails or footpaths.  They can be carriers of the infections tularemia or “rabbit fever” and spotted fever.  For this reason they should be removed immediately.  If you have been in a tick-infested area, you should carefully examine your body for ticks before retiring for the night.  The American Dog Tick may be carried into the home but will not become an established pest there.

BROWN DOG TICK
The Brown Dog Tick has only the dog as its host.  It cannot winter outdoors in Minnesota, but may be found year-round on dogs in heated kennels and homes.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. The brown dog tick is not an important carrier of human disease.
Usually, the family pet when placed in an infested kennel becomes infested with ticks and carries them back into the home.  The ticks then reproduce in the home often increasing to unusually large numbers.  They may be found on carpeting, furniture, draperies and walls and they can be most annoying.

DEER TICK
The 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).

Lyme disease is caused by a spirochete (or type of bacteria) called Borrelia burgdoferia, which affects humans.  This disease organism is vectored primarily by the Deer Tick, which attacks the white-tailed deer.  The larval stage will attack and feed on small mammals such as deer mice and the immature stage will feed on larger mammals such as dogs, deer and humans whereas the adults usually attach themselves to the white-tailed deer.

Symptoms of Lyme disease can be severe, including acute headache to more serious nervous system impairment resembling rheumatoid arthritis, an expanding red “bulls-eye” shaped rash on or near the tick bite, low grade fever, abdominal and joint pain, dizziness and stiff neck.  Medical help should be sought for the treatment of Lyme disease.

Biology:

Ticks have 4 stages in their life cycle: Egg -Larva -Nymph -Adult

1. Egg (female dies after depositing)
2. Larvae (Seed Tick - only 6 legs) Larvae Has Blood Meal
3. Nymph (8 legs) Nymph Has Blood Meal
4. Adult  (Blood Meal, Mating occurs, Male dies)

Habits:

Ticks eat a blood meal only three times in their two-year life cycle.  Mating occurs on the host organism after which the female will drop to the ground and deposit her eggs, which can number up to 5,000.  The first immature stage larvae, which are called “seed ticks,” have only 6 legs.  These seed ticks then will climb up a blade of grass and patiently wait for it’s first blood meal to come along.  Because of the difficulty of finding a suitable host, larvae can withstand long periods without feeding.  After several days of eating it will drop off the host, digest it’s food, shed its skin and emerge as an 8-legged nymph.

Like the larvae, the nymphs must be able to live without feeding for long periods of time until a suitable host comes along.  After finding a host and feeding, the nymphs molt and become adults.

The adults need to get a blood meal also, and while the female is feeding (she’s in a vulnerable position), the male will mate with her, he then dies and she will finish eating, drop off, lay her eggs and die shortly thereafter.  Then the cycle starts again!

Ticks spend most of their life on or near the ground, waiting patiently for a suitable host.  Since they cannot run, hop, fly, or even move quickly, they must climb onto an appropriate object such as tall grass or weeds, or up onto fences and siding of buildings, to then wait for a victim to come along. When they detect vibrations, exhaled carbon dioxide or even shadows from a passing host, they will fall from their perch and hope to snag onto or attach themselves to the host.

Treatment:

If possible, try to eliminate dense woody underbrush.  Cut grass and other vegetation along pathways and areas where people and pets might come into contact with ticks.  Since the American Dog Tick feeds on small mammals, a population reduction of mice, gophers, rabbits and other rodents would help to reduce the number of ticks in these areas.  Cleaning up clutter and other areas which provide harborage for rodents along with sealing or repairing rodent entry points around the house will prevent rodents, which may be infested with ticks, from nesting in or around the home.

Properly labeled insecticides (or in this case, “acaricides” because ticks are not insects) may be used in areas where ticks might congregate in the home; cracks, crevices, baseboard areas, window and door casings and the edges of carpeting.  During the spring and summer, exterior areas frequented by the dog, such as the yard, doghouse and crawl spaces should be treated. Since some vegetation will be treated, make sure the chemical is properly labeled for those areas.  When treating the yard, be sure to treat all fences, siding and plant material up to a couple of feet high.  The dog must be treated to insure the elimination of the infestation, however, this is not the pest management professional's responsibility.  This is a job for the pet owner or veterinarian.     
LOTION
For all ticks it is recommended that you use some form of repellant when venturing into possible tick infested areas.  Repellants should have D.E.E.T. as the active ingredient, and should be applied to socks, trouser legs, cuffs and other clothing, which might come in contact with tall grass etc. where ticks might congregate.