26 July 2009

What do we have here?

It's a tick! Specifically it's an American Dog Tick, aka Wood Tick, Dermacentor variabilis. The one in the picture is the only tick I've found on myself all this year so far. There's one path in a conservation area I like to go to that must double as a deer path or something. The grasses have gotten to knee-height this spring, and as you're walking through you see every other stalk has three or four black spots hanging around at the top. They hang on with their bottom two pairs of legs and wave the other pairs around to latch on to you. I was always told that ticks are slow stupid creatures. I can't vouch for their intelligence, but they aren't that slow, and they have certainly found a niche to exploit. Sometimes I couldn't get the ticks to crawl onto my shoe when I touched them on their grass stalk. But when I could, they grabbed right on.

In researching how ticks operate, I realized that for as much as I've heard about them as vectors of diseases (Lyme disease by Deer Ticks, Rocky Mountain Spotted Fever and tularemia by American Dog Ticks), I didn't know much about their operation. First off, ticks are arachnids. Eight-legged, related to spiders and mites. Secondly, ADTs are 3-host ticks, meaning that in the course of their life they will feed on three different hosts. As larvae and nymphs they feed on smaller mammals (mice, maybe birds if they can?), before tackling the larger ones (dogs, me) as an adult.

Another myth I somehow had as a lad was that ticks had one chance to make it onto an animal. I also thought they dropped from tree limbs. They would spend days crawling up a tree, out onto a branch to do their best bombardiering onto a deer, dog or person. They do not, in fact, do that. Ticks are amazingly long-lived (IMO) for something so small, as I learned at this University of Florida website. They will try many times to land on an animal if they don't make it from their grass stalk. Adults can survive two years (!) without eating. And nymphs and larvae aren't slouches either! All told, ticks are patient, deliberate parasites.

Finally, my grandfather was wrong with his advice about how to remove a tick that's bitten you. He recommended either placing a match head that had just been ignited and put out on the tick's body to make it say "I gotta get outta here!" He also said, if you're out of matches, just slap some petroleum jelly on there and it won't be able to breathe. The reason you want to do either of these, he said, is that if you pull it out the tick's "head" (really just it's mouth) may remain underneath your skin where it will continue to infect you with disease, or at least make healing a pain. Actually, you do want to pull it out, just make sure you use tweezers and not your fingernails or something. Hold on to it tight, get as close to the bite as you can, and tug it out. It won't hurt and you won't bleed. Get it out as soon as you find it, because even though it can take many hours for any possible diseases to get transmitted into your bloodstream, if you leave it hanging there out of laziness then you've reached a new low.

Headed for the counter's edge, will the tick make it to freedom?

Almost there! A cliffhanger ending! (They're really kind of quick, I had to keep putting the camera down and corralling it just to get these lame photos.)

Animalia (Animals)
Arthropoda (Arthropods)
Arachnida (Arachnids - spiders, scorpions, ticks and mites)
Ixodida (Ticks)
Ixodidae (Hard-bodied ticks)
Dermacentor variabilis - American Dog Tick

photos © 2009 Bennet Porter

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