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American Dog Tick - Dermacentor variabilis |
 Male Dog Tick on my blue jeans |
| The American dog tick is the largest of the eastern wood ticks, and the most common tick found in Illinois. They are most active during the moths of April and May, but I have encountered them into July and August - 2005, with its
dreadful drought here near Chicago has been particularly bad. (However, that may be because I rarely used mosquito repellent at all that summer.) Ticks are arachnids, and adult ticks have eight legs like
spiders. The American dog tick is reddish brown, with white or pale yellow markings. The male tick (the specimens pictured are males) is about 1/8 inch long, with the female slightly larger. She will be much bigger, about 1/2 inch when engorged with blood (eeew).
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Female Dog Tick in search of blood meal.
| Ticks are parasites, and American dog ticks are known as "three host" ticks because they use three different hosts during their development. When the larva hatches from the egg, it has only six legs, like an insect. The larva will generally latch onto the first small mammal that happens by - a vole, shrew, chipmunk, mouse or the like. After drinking blood for about four days, the larva drops off the host, and molts (sheds its skin) to become an eight-legged nymph. It then finds the next host - generally a larger
mammal such as a raccoon, deer or opossum. Once again, the process repeats and the nymph becomes an adult tick. Adult ticks will find a third host, a large mammal. The male tick supposedly will not feed, but mate with the female while she is feeding. (I can tell you from bitter experience, male ticks rarely bite, but they do bite.) After mating, both genders drop off the host and the female will lay up to 4,000 eggs in the soil. American dog ticks do not carry Lyme disease, but they are carriers of Rocky Mountain spotted fever.
Deer ticks (Fig 1.) can carry Lyme disease, the most commonly diagnosed tick-borne bacterial disease in the United States. It has also become a veterinary problem, believed to cause joint-related problems in animals (dogs and horses, mostly) exposed to the Lyme bacteria. Lyme disease was first reported in Connecticut in 1975, and is named after the town of Lyme in which the disease was first observed. |
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Ticks have flattened bodies designed to fit into small cracks and crevices - advice to "tuck your pants into your socks" is ludicrous on its face; ticks will crawl under your clothing at will. I have found deet-based insect repellents marginally effective at keeping them off me. I cannot speak for flea and tick dog collars or the like, I have not a dog. I can tell you this: if you go into the weeds at the Winfield Mounds Forest Preserve in Winfield, Illinois during the months of April and May, you will have dog ticks on you when you come out. |
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