Into the Woods

In the best of all possible worlds, there’d be no need for insecticides. But permethrin, at least, seems to be pretty benign. Permethrin is a synthesized version of pyrethrin, an organic insecticide made from chrysanthemums. The most scary thing about permethrin is how persistent it is. Clothing treated with permethrin can remain effective against insects (and ticks) through up to six washings. Still, it’s not very toxic to humans, especially after it has dried.

Each year, the tick situation seems to get worse. When I was a kid, I knew of only one kind of tick, the kind of tick that dogs got. But now there are several varieties, and I can’t distinguish one from another. I do know, though, that these days we have very small ticks, especially in the spring and early summer. They’re harder to detect because they’re so small, and their bites are just as offensive as larger ticks.

I have found that treating clothing with permethrin is very effective against ticks. It actually kills ticks — slowly, but quick enough to keep them from biting. On most summer days, two levels of defense are needed — permethrin for things that crawl, and Deet for things that fly.

The Center for Disease Control recommends the use of both permethrin and Deet. Also, here’s a nice article from NPR on permethrin. According to the article, it was the U.S. military that developed the method of treating clothing with permethrin.

Permethrin in liquid form is said to be toxic to cats. It’s best to treat clothing outdoors on a clothesline and leave things hanging until the permethrin dries. Don’t forget to treat your shoes and socks.