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Archive - June 2020

What are Ticks? - Ticks are invertebrate animals. They are classified in the Phylum Arthopoda. Arthropods are invertebrate animals with jointed legs, an exoskeleton and a segmented body. This group contains a huge number of species, from scorpions to crayfish. Ticks are further classified in the smaller groups, the Class Arachnida, Subclass Arachnida (scorpions, pseudoscorpions, spiders, daddy-long legs, mites and ticks) and Order Ixodida (mites and ticks). Twenty species of ticks live in Illinois, but only about five of them are seen regularly by people.

What Do Ticks Look Like? - Ticks have two body sections: the gnathosoma and the idiosoma. The gnathosoma contains the mouthparts. The idiosoma has the legs, digestive tract and reproductive organs. The adult tick has eight legs, while the larval tick has six legs. The body is flattened so that its back (upper) side is not far from its belly (lower) side. Ticks do not have antennae.

There are two groups of ticks: soft-bodied and hard-bodied. In Illinois, you are more likely to see hard-bodied ticks. The soft-bodied ticks in our state tend to live on bats and birds. Below you will find some information about five types of hard-bodied ticks that you might see in Illinois.

This species is the most common tick in Illinois. The adults feed on humans (Homo sapiens) and medium- to large-sized mammals, such as dogs (Canis familiaris) and raccoons (Procyon lotor).

The back-legged tick has been found in many Illinois counties, but in recent years it has been common only in specific areas, mainly in northern Illinois. The larvae in the southern part of the state feed on lizards and birds. In northern Illinois, the larvae feed on mice and other small mammals. The nymph stage feeds on mice, larger warm-blooded animals and people. Adults feed on white-tailed deer (Odocoileus virginianus).

lone star tick Amblyomma americanum Photo © James Gathany

All stages of this tick feed on a variety of animals, including humans. Although found statewide, this species is most common in the southern one-half of the state.

The brown dog tick is a tropical species that cannot survive outdoors in Illinois' winters. Also known as the kennel tick because it is found mainly in kennels or in homes with a dog, it feeds on dogs and can carry out its life cycle indoors.

winter tick Dermacentor albipictus Photos © Maine Medical Centre Research Institute

The winter tick is often seen in large numbers on white-tailed deer. It also feeds on other large mammals, like cows (Bos taurus) and horses (Equus ferus caballus). This species attaches to the host as a larva and remains attached throughout its life.

How Big are Ticks?
In Illinois, most adult ticks that have not recently fed are about 1/8 inch long. After feeding, the idiosoma of some female ticks may enlarge to about 1/2 inch long.

Where Do They Live?
Ticks prefer shady areas with many plants.

How Do They Reproduce?
The life cycle of a hard-bodied tick can take up to three years. There are four stages: egg; larva; nymph; and adult. The adult female feeds on the blood of her host, and then lays eggs. The eggs hatch to the larval form of the tick. After feeding, the larval form transforms to the nymph stage. The nymph feeds, then molts to the adult form.

What Do They Eat?
Ticks are external parasites of mammals, birds, reptiles and amphibians. They attach to the outside of the host animal and feed on its blood. A hard-bodied tick needs three blood meals to complete its life cycle.

Does Anything Eat Them?
Some mites, roundworms and birds eat ticks.

What Else Should I Know About Them?
Because they feed slowly, eat blood and must feed several times in their life cycle, ticks can transfer some diseases. Rocky Mountain spotted fever (American dog tick, lone star tick), tularemia (American dog tick, lone star tick) and Lyme disease (black-legged tick) are among the diseases that ticks can transmit. Most ticks are not infected, but those in some areas are more likely to be infected than others. Local health departments and the Illinois Department of Public Health (217-782-2016 or Illinois ticks surveillance maps Internet site.) can provide more information about ticks and the diseases that they can carry. If you should experience a rash that looks like a bull's-eye, a rash anywhere on your body or an unexplained illness with a fever after being bitten by a tick, you should visit your doctor. Diseases carried by ticks are treatable, but the treatment should begin quickly.

Ticks find their host by waiting at the tip of grasses or shrubs. When an animal passes by and touches the plant, the tick quickly crawls onto the animal.

Depending on the weather, ticks are capable of being active all year. The temperature must be at least 45 degrees Fahrenheit for ticks to move about.

Here are some tips to prevent tick bites if you are going to be in an area where ticks are present.
- Wear long-sleeved shirts, long pants, boots and a head covering.
- Apply insect repellent that has 10 percent to 30 percent DEET to your clothes, following the instructions on the label.
- Walk in the center of trails so that plants don't brush against you.
- Check yourself, other family members and your pets every two to three hours for ticks.

Podcast and Resources

​Illinois Department of Public Health - 217-782-2016.

Illinois ticks surveillance maps Internet site.