The American dog tick (Figure 1), Dermacentor variabilis, is about 5 mm long with short stout mouthparts. It is dark brown with light wavy lines or reticulations on its back.
The lone star tick (Figure 2), Amblyomma americanum, is about 5 mm in length or less with long mouthparts. It is light reddish-brown with a central white spot on the back of most adults.
The brown dog tick (Figure 3), Rhipicephalus sanguineus, is about 5 mm long with short, stout mouthparts. It is distinguished from the American dog tick by its dark reddish-brown color and lack of any white markings.
The deer tick (Figure 4), Ixodes scapularis (formerly Ixodes dammini), is a small tick about 2-3 mm in length with long mouthparts. It is off-white or reddish when fed and has black legs.
The size of a tick varies with sex and lifestage (Figure 5).
Ticks generally live in shady, moist ground litter, but will climb to areas with tall grasses, bushes, brush, and woods in order to find host animals. They can also be found in lawns and gardens, on the edges of woodlands, and around stone walls where small rodents thrive. Ticks cannot jump or fly and generally do not drop from trees onto hosts; they are acquired through direct contact. When a tick finds a host, it will crawl to a protected area- often the groin, armpit, scalp, ears, back of knees, navel, or neck. Ticks generally wander for several hours before beginning to feed by inserting their mouthparts into the host's skin. If a tick is not detected, it will feed for several days before dropping off the host.
Rocky Mountain Spotted Fever
RMSF is a disease caused by rickettsia bacteria. A tick needs to be attached for four to six hours in order to transmit RMSF to its human host. The first symptoms noticed are usually severe headache, chills, fever, muscle aches, nausea, vomiting, and other flu-like symptoms. These first symptoms usually start 2 to 12 dafter the tick bite. By the third day after the bite, a red rash develops on the wrists and ankles, in most cases, and often spreads to the entire hand or foot (Figure 6). A blood test is needed to confirm the disease, and early use of antibiotics has a very high rate of cure. In recent years in Virginia an average of only 20 cases and one death per year have been reported.
Lyme disease is caused by the spirochete bacteria Borrelia burgdorferi. A tick must be attached for at least 24 hours in order to transmit the disease organism to the host. The disease initially develops as an oblong rash, usually 2 or more inches in size, with a clear center that develops at the site of the tick bite (Figure 7); however, only 70% of people develop this symptom. Within two days to a few weeks later people usually develop flu-like symptoms such as nausea, headache, fever, and general stiffness of the neck joints. Chronic symptoms of a small percentage of untreated people include arthritis and nervous system complications. In Virginia, about 125 cases per year are reported, mainly from the eastern and central parts of the state.\
Do not squeeze the tick's body or use vaseline, a hot match, alcohol, or any other irritant in an attempt to kill or remove the tick. These methods will actually cause the tick to regurgitate, increasing the risk of infection from the bacteria located in the midgut.
Once the tick has been removed, place it in a vial or jar of alcohol to kill it. Label the jar with the date, body location where the tick was attached, and location where it may have been picked up. This information may be helpful to a doctor if signs of disease occur. Clean the bite wound with an antiseptic such as witch hazel, rubbing alcohol, or iodine.
Reviewed by Bonnie Appleton, Extension Specialist, Hampton Roads Agricultural Research and Extension Center
Virginia Cooperative Extension materials are available for public use, re-print, or citation without further permission, provided the use includes credit to the author and to Virginia Cooperative Extension, Virginia Tech, and Virginia State University.
Issued in furtherance of Cooperative Extension work, Virginia Polytechnic Institute and State University, Virginia State University, and the U.S. Department of Agriculture cooperating. Alan L. Grant, Dean, College of Agriculture and Life Sciences; Edwin J. Jones, Director, Virginia Cooperative Extension, Virginia Tech, Blacksburg; Jewel E. Hairston, Administrator, 1890 Extension Program, Virginia State, Petersburg.
May 1, 2009