At one time or another most people will experience the aggravation of tick bites. Knowledge of tick biology and habitats, as well as methods of tick control, can help you avoid this problem.

     Most ticks are parasites of warm-blooded animals. Their bites are not only annoying and painful but may result in localized skin inflammation, secondary infection and possible introduction of disease-causing microorganisms.

     Ticks are not insects but are closely related to mites, spiders and scorpions. Adult ticks have eight legs, while adult insects have only six. Also, the tick's body is fused into a single region instead of having the head, thoracic and abdominal regions typical of insects.

     Ticks are grouped into two families: 1) the "hard ticks" (Ixodidae), which have a hard smooth skin and an apparent head; and 2) the "soft ticks" (Argasidae) which have a tough, leathery, pitted skin and no distinguishable head. Both groups contain species that attack humans and animals.

LIFE CYCLE

     Ticks have four developmental stages: egg, six-legged larva, one or more eight-legged nymphs and adult. Hard ticks usually mate on the host animal. The female then drops to the ground and deposits from 3,000 to 6,000 eggs, which hatch into larvae or "seed ticks." Larvae climb nearby vegetation where they collect in large numbers while waiting for small rodents or other vertebrates to pass within reach. After a blood meal on the host, the engorged larvae drop to the ground. shed their skins (molt) and emerge as nymphs. Like larvae, the nymphs await the passage of a host, engorge themselves with blood, drop to the ground, molt and become adults. Adult ticks seek host animals and after engorgement, mate.

     Male hard ticks usually mate with one or more females and then die, although some may live for several months. Females die soon after depositing their eggs in protected habitats on the ground. The life cycle requires from as little as 2 months to more than 2 years, depending on the species.

Figure 1. Typical developmental stages for ticks.

     This life cycle is characteristic of tick species which commonly infest humans and their pets in Texas . However, some species feed as larvae, nymphs and adults on only one host during the life cycle.

COMMON TICK SPECIES IN THE SOUTHERN UNITED STATES

Disease Transmission by Ticks TOP OF PAGE
American Dog Tick	Rocky Mountain Spotted Fever Tularemia
Male                   Female	Photos from Ticks and Tick-Borne Diseases in North Carolina (publication AG-428)
Black Legged Tick	Primary vector of lyme disease Human granulocytic ehrlichiosis
Male Female	Photos from Ticks and Tick-Borne Diseases in North Carolina (publication AG-428)
Brown Dog Tick	Canine ehrlichiosis Canine bebesiosis
Male Female	Photos from Ticks and Tick-Borne Diseases in North Carolina (publication AG-428)
Lone Star Tick	Tularemia Lyme disease
Male Female	Photos from Ticks and Tick-Borne Diseases in North Carolina (publication AG-428)

Resources used:
James E. Keirnes, PhD
US National Tick Collection, Georgia Southern University

TOP OF PAGE

American Dog Tick (Dermacentor variabilis)

     The American dog tick attacks a wide variety of hosts, including humans, but rarely infests homes. Adults are chestnut brown with white spots or streaks on their backs. Unfed adults are about l/8-inch long. Engorged females become slate gray and may expand to a length of l/2-inch. Larvae and nymphs feed mostly on small rodents, while adults feed on dogs, cattle, other animals and humans. These ticks are widely distributed over the eastern two-thirds of Texas but are most abundant in coastal and other humid areas. They are attracted by the scent of animals, and humans most often encounter them near roads, paths, trails and recreational areas. Although present the year round, American dog ticks are usually most numerous in the spring.

     The female dog tick lays 4000-6500 eggs and then dies. The eggs hatch into seed ticks in 36-57 days. The unfed larvae crawl in search of a host and can live 540 days without food. When they find a small rodent, the larvae attach and feed for approximately 5 days. The larvae then drop off the host and molt to the nymphal stage. The nymphs crawl in search of a rodent host, attach to a suitable host, and engorge with blood in 3-11 days. Nymphs can live without food for up to 584 days.

     Adults crawl in search of dogs or large animals for a blood meal. Adults can live for up to 2 years without food. American dog tick adults and many other species can be found along roads, paths, and trails, on grass, and on other low vegetation in a "waiting position." As an animal passes by, the tick will grasp it firmly and soon start feeding. The males remain on the host for an indefinite period of time alternately feeding and mating. The females feed, mate, become engorged, and then drop off to lay their eggs.

     The American dog tick requires from 3 months to 3 years to complete a life cycle. It is typically an outdoor tick and is dependent on climatic and environmental conditions for its eggs to hatch.

TOP OF PAGE

Brown Dog Tick (Rhipicephalus sanguineus)

     The brown dog tick rarely bites humans, but infestations are frequently found on dogs and in the home.

     Adults are reddish-brown. Unfed adults are l/8-to 3/16-inch long. The adult female lays a mass of 1000-3000 eggs after engorging on a dog's blood. Engorged females are about l/2-inch long. They feed almost exclusively on dogs, where they attach to the ears and between the toes. They are widely distributed in Texas and rarely attack man.

     The eggs hatch in 19-60 days into a six-legged, small seed tick. The seed tick takes a blood meal from dogs when they are available. The larvae are so small they won't be noticed on the dog unless a number are together. The seed tick remains attached for 3-6 days, turns bluish in color, and then drops to the floor. After dropping from the host, the seed tick hides for 6-23 days before motling into an eight-legged, reddish-brown nymph. It is now ready for another blood meal and again seeks a dog host.

     The nymphs attach to dogs, drop off, and molt to the adult in 12-29 days. As a reddish-brown adult, it again seeks a blood meal, becomes engorged, and is bluish in color, reaching about 1/3 inch in length.

     Unengorged larvae, nymphs and adults may live for long periods of time without a blood meal. Adults have been known to live for as long as 200 days without a blood meal.

     Brown dog ticks become a problem in and around human habitation or dog kennels when ticks fall off infested dogs as engorged larvae, nymphs or adults. Inside the home, the ticks hide behind baseboards, window casings, window curtains, ceiling and picture moldings, bookcases and cabinets, as well as inside upholstered furniture and under the edges of rugs. Outdoors, they hide near building foundations, in crevices between porch floorings and sidings and beneath porches.

TOP OF PAGE

Lone Star Tick (Amblyomma americanum)

     Adult lone star ticks are various shades of brown or tan. Females have single silvery-white spots on their backs and males have scattered white spots. Unfed adults are about l/3-inch long, but after feeding females may be l/2-inch long. Larvae and nymphs parasitize small wild animals, birds and rodents, while adults feed on larger animals. All three stages will bite humans. These ticks live in wooded and brushy areas of Texas and are most numerous in underbrush along creeks and river bottoms and near animal resting places. Lone star ticks are present throughout the year, but peak adult and nymphal populations may occur from March to May. A second nymphal peak may occur again inJuly or August, while peak larval activity is reached in mid-June or July.

TICKS AND DISEASE

     When feeding, the tick makes a small incision in the skin of the host and inserts barbed piercing mouthparts to remove the blood. Most species cause little or no pain to their hosts at the time offeeding, but some, such as the lone star tick, cause a painful wound. Ticks can transmit diseases by infecting hosts with microorgranisms carried on their mouthparts or in salivary fluids.

     Many disorders and diseases can be traced to tick bites, including 1) dermatosis, or inflammation, itching and swelling at the site of the bite; 2) envenomization, or inoculation of toxic fluids; and 3) exsanguination, or anemia resulting from the loss of large amounts of blood because of a severe tick infestation.

     The American dog tick is also known to cause paralysis in dogs and children where ticks attach at the base of the skull or along the spinal column. Paralysis is caused by a toxic secretion produced by the feeding tick. When the tick is removed, recovery is rapid, usually within 8 hours. Sensitized animals may become paralyzed by tick attachment anywhere on the body.

     Also known as tick typhus, Rocky Mountain spotted fever is caused by a bacteria-like microorganism, Rickettsia rickettsii. Rocky Mountain spotted fever rickettsiae are acquired by an American dog tick when it takes a blood meal from an infected animals. These bacteria are not harmful to most wild and domestic animals, but they are extremely pathogenic to humans and dogs. Rocky Mountain spotted fever is normally a disease of wild animals, but people can be infected while camping or hiking in tick-infested areas if they are bitten by an infected tick. In addition, pets may carry an infected tick into living areas. The disease organisms can also be passed through the egg of an infected tick and from stage to stage in the life cycle. Fortunately, only a small percentage of American dog ticks found in nature are infected.

     Symptoms of Rocky Mountain spotted fever include headache, fever, chills, aches, pains, and sometimes nausea. These symptoms are usually accompanied by a rash that starts on the wrists and ankles. Because Rocky Mountain spotted fever is easily cured with antibiotics, a person exhibiting any of these symptoms 2 to 14 days after a tick bite should consult a physician at once. If left untreated, Rocky Mountain spotted fever can cause death. Lone star and American dog ticks are carriers of Rocky Mountain spotted fever and tularemia.

     Lyme disease is transmitted primarily, if not exclusively, by ticks. The primary vector is the deer tick (Ixodes dammini). The American dog tick and the brown dog tick are not considered important vectors of Lyme disease. Lyme disease is a serious problem in the Northeast and Great Lakes regions of the U.S. However, in 1989 there were 82 confirmed cases of lyme disease reported by the Texas Department of Health, with the majority of these cases being reported from the eastern and northeastern portions of the state. The deer tick is not prevalent in Florida, but species that are close relatives and are capable of transmitting Lyme disease are common throughout the state. When in habitats likely to be infested with ticks, precautions should be taken to prevent lyme disease.

     Humans, particularly those who work or vacation in heavily tick infested areas, who experience the onset of symptoms resembling a febrile (fever-like) disease and recall being bitten by a tick 10 to 14 days earlier should mention this association to their physician. Brown dog ticks carry diseases to humans and animals in Africa and the Mediterranean region but are not known to transmit human disease in the U.S. but are capable of transmitting canine piroplasmosis among dogs.

TOP OF PAGE

FREQUENTLY ASKED QUESTIONS ABOUT TICKS AND DISEASE

     Few pests evoke as many questions from people as ticks. Besides their repulsive appearance, ticks are vectors of potentially debilitating and life-threatening diseases. Lyme disease, in particular, has attracted national attention and is now the number one arthropod-borne disease in the United States. Although Lyme disease is more prevalent in eastern and midwestern states, media coverage has prompted many questions and concerns from citizens.

What is Lyme disease?

     Lyme disease is a potentially serious bacterial infection, transmitted through the bite of certain species of ticks. The disease affects humans and a wide range of animals including pets and livestock. Lyme disease manifests itself in many ways and if left untreated may progress through several stages. The disease is difficult to diagnose clinically because early symptoms often mimic the flu (i.e., fatigue, headache, stiffness or pain in neck, muscles or joints, fever, or swollen glands). The most definitive early symptom is a gradually expanding circular or oval-shaped red rash. This rash only develops in about 70% of infected individuals, however, and may be overlooked.

     Persons who experience any of the above-mentioned symptoms after being bitten by a tick (or having spent time in tick-infested areas), should consult a physician immediately. Lyme disease can be treated successfully in these early stages with antibiotics. As the disease progresses, it becomes more difficult to manage. Later symptoms of infection may include heart and neurological disorders, and arthritis.

How can I tell if the tick I just removed is capable of transmitting Lyme disease?

     The two tick species which are most common in Kentucky are the American dog tick and the lone star tick. Neither has been shown to transmit Lyme disease. The adults of these species are comparatively large, being about the size of a pencil eraser. Adult ticks of the variety most often responsible for transmitting Lyme disease (e.g., Ixodes dammini), are considerably smaller -- adults are about the size of the head of a pin. Therefore, if the tick that was found is pencil eraser-size or larger, it's probably an American dog tick or lone star tick and, consequently, not a vector of Lyme disease.

     Definitive tick identification, however, requires the expertise of an entomologist. Immature stages of lone star and Ixodes ticks are both extremely small (about the size of a sesame seed), and are easily mistaken for one another. The UK Entomology Department will identify ticks at no charge. Specimens should be sent to Dr. Greg Burg in alcohol-filled vials accompanied by the date and county from which the tick was collected.

      It should be noted that ticks capable of transmitting Lyme disease must be attached for at least 24 hours for infection to occur. A person cannot become infected simply by having a tick crawl over their skin or clothing.

Just how prevalent is Lyme disease in Kentucky?

     Fifty-one cases of Lyme disease were reported to the Kentucky Department of Health Services during 1985-90. Forty-four additional cases were reported in 1991. It is unclear how many of these infections actually resulted from tick bites received in Kentucky, since many of the victims had previously visited or lived in other states where Lyme disease occurs. Agencies within our state also are surveying for ticks and animal hosts infected with the Lyme disease bacterium (Borrelia burgdorferi). Neither the American dog tick nor lone star tick (the two most common ticks in Kentucky) appears to be a vector of the disease. And to this point, none of the proven tick vectors of Lyme disease (Ixodes spp. ) have been found.

     In summary, Lyme disease is present in Kentucky but the mechanism of transmission is not yet known. Until more is known, people should be aware of the early symptoms of the disease, and should see a physician if they suspect they may have been bitten by a tick.

I've heard the term "deer tick" used when describing ticks which transmit Lyme disease -- don't we also have deer ticks in Kentucky?

     "Deer tick" is the term commonly used when referring to Ixodes dammini, the principal vector of Lyme disease in the Northeast. In Kentucky, the same term is used when referring to nymphal lone star ticks which are commonly found in western and south central portions of the state. Lone star ticks are not considered to be a vector of Lyme disease, although they can transmit Rocky Mountain spotted fever.

How important is Rocky Mountain Spotted Fever (RMSF) in Kentucky?

     Rocky Mountain spotted fever has not received the media attention of Lyme disease, but is potentially more deadly. Each year there are roughly 10-30 reported cases of RMSF in Kentucky. (there were 31 reported cases in 1991). Although RMSF can be successfully treated with antibiotics, medical experts estimate that without treatment, 20% of those infected could die.

     In Kentucky, the primary vector of RMSF is the American dog tick, although lone star ticks may also transmit the pathogen (a rickettsia). Symptoms of RMSF are flu-like, accompanied by headaches and a very high fever (104-106 degrees F) two to twelve days after being bitten by a tick. The most characteristic symptom of RMSF is a rash that appears on about the second to fifth day on the wrists and ankles, later spreading to other parts of the body. In most cases, the tick must be attached for at least a day for infection to occur.

TOP OF PAGE

TICK REMOVAL

     Because tick movements and bites are seldom felt, careful and frequent examination for ticks on the body and clothing is imperative. Early removal is important since many disease organisms are not transferred until the tick has fed 2 to 8 hours. Always remove the tick with its mouthparts intact. Hasty removal of an attached tick can break off the mouthparts. Mouthparts left in the skin may cause secondary infection. To relax tick mouthparts for easy removal, touch the tick with a hot needle or a few drops of camphor, alcohol, turpentine, kerosene or chloroform. The best method is to grasp the tick firmly with tweezers and remove it with a slow, steady pull. Avoid touching the tick vvith your bare hands. If an infected tick is crushed between the fingernails the organism responsible for Rocky Mountain spotted fever may enter through a cut or abrasion.

     Should you find a tick attached to the skin, the following procedures should be used for removal:

     Use blunt tweezers or disposable gloves to handle the tick. If fingers must be used, shield them with a tissue or paper towel. Infectious agents may be picked up through mucous membranes or breaks in the skin by handling infected ticks. This is especially important for people who "detick" pets or other domestic animals, as ticks infesting dogs and other domestic animals can carry Lyme disease or several other diseases capable of infecting humans.

     Grasp the tick as close to the skin surface as possible. This reduces the possibility of the head detaching from the body upon removal.

     Pull the tick out straight out with a steady, even pressure. Do not twist or jerk the tick as this may cause the mouthparts to break off and remain in the skin, increasing the chances of infection. Continue the steady pressure even if the tick does not release immediately-it may take a minute or so of pulling to cause the tick to release.

     After removing the tick, thoroughly disinfect the bite site and wash your hands with soap and water. Home remedies such as applying vaseline, grease, or a hot match to the rear of the tick are not recommended. These practices cause the tick to salivate and can actually increase the chance of getting the disease.

     After removing the tick, you may wish to preserve it in alcohol-plain old rubbing alcohol will do. Be sure to label the container with information about the time and place where the tick bite occurred. This activity will help you to remember details of the incident if the rash or other symptoms associated with Lyme disease appear later. This information will also be of help to a physician in diagnosing the illness.

     Fortunately, prompt treatment with antibiotics is very effective in curing Lyme and other tick-borne diseases, but most people agree that protecting yourself from tick bites in the first place is the best approach

                                                                TICK CONTROL

Tick Surveys

     Sometimes information is needed about tick infestation in a given area-the presence or absence of ticks, tick density or tick species. To obtain this information, ticks can be removed from host animals in the area. Clues often can be obtained by studying past and current land uses. For example, if the land was once in agricultural production but has since been abandoned it probably supports a heavy population of field mice and, consequently, may be a tick-infested area. Immature ticks inhabit "mousy areas," while adults are abundant along trails traveled by humans and large animals. For a more complete survey, a small, square piece of white flannel cloth can be dragged slowly over low vegetation beside trails and roads. Waiting ticks will attach themselves to the cloth and can then be studied to determine the species and degree of infestation.

TOP OF PAGE

Protection from Ticks

     To obtain some degree of protection against ticks, keep clothing buttoned, shirt tails inside trousers and trouser legs inside tops of socks. A ring of masking tape with the sticky side out placed around the top of boots will trap ticks that are ascending to look for a site to attack. Do not sit on the ground or on logs in brushy areas.

      Persons who must be in areas suspected of supporting infestations should examine their clothing, body and hair at least twice daily to remove ticks promptly.

     Clear or burn brush along trails and cut weeds and grass in recreation areas. In residential areas, maintain closely cut and well-kept lawns to help control both ticks and their small rodent hosts.

      Repellents containing diethyl-m-tolumide, dimethyl phthalate, dimethyl carbate or ethyl hexandiol will protect exposed skin but will not stop ticks from crawling under clothing to reach untreated portions of the body. Applying these materials to the entire body might prevent tick bites for a while, but such extensive treatments often are impractical and may be hazardous to health. Permanone, a tick repellent containing a synthetic pyrethrin, may be applied to clothing (do not allow skin contact). Treatment with this product may provide protection for a day or longer.

TOP OF PAGE 

Chemical Control

     If a tick infestation occurs, treat the home, yard and pets at the same time. Examine dogs and cats frequently for ticks. Heavy infestations on pets should be handled by a veterinarian.

     Light infestations in buildings usually can be controlled with a household residual spray. Apply the insecticides only as light, spot treatments to areas where ticks are found or suspected to be hiding. DO NOT USE THESE CHEMICALS FOR TREATING PETS. Treatment around baseboards, window and door casings, wallcracks and in pet sleeping quarters is necessary. To control severe infestation in the home, remove the pet from the house and make repeated applications of approved insecticides at 2- to 4-week intervals. Select a spray that does not have an objectionable odor and will not stain paints, wall paper, tile or rugs.

     Tick control in home lawns and other vegetated areas usually can be obtained with residual sprays or dusts. Give particular attention to spray applications around building foundations and along roadsides, animal trails and paths used by people.

     The USER always is responsible for the effects of pesticide residues on his own premises, as well as problems caused by drift from his property to that of others. Always read and follow carefully all instructions on the product label.

TOP OF PAGE

PERMETHRIN SFR