Saturday, November 28, 2009

Maybe you shouldn't lean back on the railing just now.

We're solitary people by nature, but every now and then someone visits. We were sitting out on the deck enjoying drinks with some friends from my husband's work. I glanced at the deck railing and saw a bit of movement behind Karen's head. Bee? Moth? June bug? No, it was something a little more unusual.

This is a Wheel Bug, Arilus cristatus. They're rather large and dramatic-looking. Part of the drama is due to the size: this one was easily an inch long--more if you count the long antennae. Its movements are eerily robotic: it walks slowly, moving one stick-like leg at a time. It also flies clumsily, with a loud buzzing sound. The whole time I was trying to get some pictures, I kept thinking that if it flew and landed on me while I was trying to focus the camera, I'd have a stroke and die. There was a particularly scary moment when the auto-focus was having a hard time, zooming in and out. By the time it stabilized, I was looking at an empty piece of railing. "Hm. I see where the bug was. I'm kind of afraid to look around to see where it is."

I can safely call this a bug because it really is one of the true bugs, belonging to the order Hemiptera. True bugs have mouths that have evolved into beaky sucking things. In this picture, you can see the "beak" tucked back under the head.

Most bugs use that structure (really it's called a "rostrum") for sucking the sap out of plants, like aphids. A good look at a Wheel Bug's rostrum makes you think that it's after something a little livelier than your Aunt Miranda's rosebush. You'd be right: this is a member of the family Reduviidae, the formidable Assassin Bugs. I keep seeing this family of insects referred to as "the gardener's best friend," although I don't know a lot of gardeners who can really get on board with that assessment. A Wheel Bug doesn't look like anyone's BFF. It preys on hapless insects, piercing them with that rostrum, and injecting them with a powerful digestive enzyme. It can then easily suck up the liquified bug innards as though it was sipping a chocolate malt. If handled, it's also happy to pierce human flesh and inject that same enzyme, which is reported to be a spectacularly painful event.


  1. So far, this is my favorite insect. There's something prehistoric about them. We only see a few each year, but it's a real treat.

  2. "Prehistoric" is definitely one of the words that I think of when I see one.

    They're one of my favorites, too. I found a dead one that had been accidentally slammed in the front door, and was just heartbroken.