Little Green Boxes

Heading out the driveway and down the road the other day I noticed something hanging in a tree at the corner of the property:

I didn’t have time at the moment, but a little later I had a chance to look at it more closely. It’s cardboard, three-sided, and open on the sides. And I was unaware that it had been put in my tree (it’s in the portion of the tree that hangs over the ditch).

And then I began to see them elsewhere. In other trees (sometimes you have to look closely)...

...and on fenceposts:

Closer inspection finds that these are gypsy moth traps. Apparently the Illinois Department of Agriculture places traps every year to monitor the population and make decisions about where and whether to treat for them. I don’t know if they’ve done that in our area before and I just haven’t noticed, or if this is new for us.

I’ve heard of gypsy moths before, but I didn’t really know anything about them. There’s info on the Department of Agriculture Page linked above and, of course, on Wikipedia, but the gist, from Wikipedia, is that this is an introduced invasive species. It first appeared in the northeast Atlantic States - beginning with Massachusetts - in 1869, and has been diligently working its way westward ever since. It now appears in eastern Wisconsin and northeastern Illinois, and it is problematic because its larvae will "consume the leaves of over 500 species of trees, shrubs, and plants". According to Wikipedia this moth is "one of the most destructive pests of hardwood trees in the eastern United States". Among other things, the eggs hang out on firewood, which is at least part of the reason you’ll see materials asking that you only use local firewood at campsites.

This is one of those cases where an enterprising soul thought he’d be doing a solid by bringing the moths over from Europe - in this case to try and breed them with silk moths to get a version of a silk moth that wasn’t such a fussy eater. Turns out that Étienne Léopold Trouvelot’s skills as an astronomer may not have translated well to his amateur interest in entomology - the two species cannot interbreed. But what gypsy moths can do however, apparently, is get away from you and escape into the woods around your home. Which, it would seem, is how you can have craters named for you on both the moon and Mars, but still have "introducing the gypsy moth to North America" be the only thing listed in the "known for" section on your Wikipedia page.

All of this makes one curious as to what might be in those traps, but they should not be disturbed, so I’ll just continue to wonder. But at least now I no longer have to wonder what those little green boxes I keep seeing are for...