Whence a caterpillar crossses your path

I came across a caterpillar today that was too cool to pass up sharing. You're in for a treat.

I was walking to the science center on campus today and looking around the fringes of the grass, as per usual, when I spotted a caterpillar on the sidewalk. It was serendipitous because I was just thinking about how as an entomologist, I've been training myself to focus on small things and watch for movement that might be overlooked by someone who doesn't constantly look for bugs. It was an interesting moment.

I noticed a small green thing that looked like a leaf, and at first thought it was. A breeze had just blown some leaves across the path, but this was a little different. It's a good thing I don't have a habit of crushing leaves, or this story would be sad.

Sidewalk is not its natural habitat.

A-ha! My first thought: "Definitely not a leaf." My second thought: "Sphingidae." This caterpillar has very pretty colors, like a grape popsicle shoved into a lime. The first thing to notice after the colors is the horn at the end of its abdomen--that's an identifying feature for the sphinx moths, family Sphingidae. Sphingidae is easily one of the coolest (if not THE coolest) families of moths, and they're easily identified by the posterior horn that the caterpillars have. (Unless you're dealing with Abbot's Sphinx - Sphecodina abbottii. In that case, the caterpillar will be staring right back at you with its raised knob that resembles an eye.)

Hemaris diffinis - Snowberry Clearwing

This Sphingid caterpillar is the Snowberry clearwing, Hemaris diffinis, which turns into a beautiful moth. When it reaches that stage, it will have clear wings (hence the common name) and look similar to a bumblebee. How cool is that? Notice the black dots around the spiracles on the side of the caterpillar, and how the horn changes colors from yellow to black towards the tip. Marvelous! While I was moving the caterpillar (first by stick, but when it wouldn't cooperate, just by picking it up), I turned around and noticed another person coming up the sidewalk behind me, looking at me like I was crazy. I tried to explain that I was moving a caterpillar so that it wouldn't be squished, but I'm pretty sure it didn't make me seem less crazy to him.

This is a common occurrence in my life.