While out on one of my compulsive monarch butterfly searches, I happened to cross paths with two other insects that I had never noticed before.
I initially said that I’d never seen them before, but invariably, I run across photos of species like this from 10 years ago that I’d completely forgotten about. So, I’ll hedge my bets and simply say that they didn’t make a memorable impression on me.
The first of these two insects was a rather attractive caterpillar that I found munching away on milkweed leaves. I was examining milkweed plants in the hopes of spotting a few more monarch caterpillars, but alas, none were present. Instead, I found about two dozen of these other caterpillars, which I thought was strange, because I wasn’t aware of any other caterpillars that could deal with the toxic, latex-infused sap of the common milkweed.
Well, one of the things I most love about exploring is the chance to learn something new. Confronted with what seemed to be a large population of caterpillars that I’d either never seen, or never bothered to identify in the past, I picked up my “Princeton Field Guide to the Caterpillars of Eastern North America” and started browsing.
Since I’m left-handed, I started at the back of the book and let the pages flip by in quick succession. I had only barely begun my first run when I almost immediately spotted the caterpillar I was looking for.
Meet the milkweed tussock caterpillar (Euchaetes egle). As with all caterpillars, this organism is, in fact, that larval form of a species of lepidoptera (the moths and butterflies). What is interesting is the fact that the adult moth is so drab and uninteresting that the species is named for the caterpillar.
The author of the field guide to caterpillars mentions that schoolteachers are often the first to alert him to the presence of large clusters of the gregarious caterpillars, which they find while they are out looking for monarch caterpillars. I don’t have the author’s phone number, but wow was he spot on. Milkweed tussock caterpillars are more than happy to munch away on the leaves of older milkweed plants, and can be found from June on — maybe you can find one of your own.
The next insect that I crossed paths with was a tree cricket. This particular individual was a female, made easy to identify by the long ovipositors projecting from the base of her abdomen. What wasn’t easy for me was coming up with an identification. I have another book, the “Guide to Night-Singing Insects of the Northeast,” which focuses only on crickets and katydids, but the key field marks weren’t visible in my photos.
Another problem I ran into was the fact that this particular female tree cricket appears to have some coloration that doesn’t conform to any of the species that I looked at. According to my field guide, there are six species of tree crickets that can be found in our area. The most notable of these species is the snowy tree cricket (Oecanthus fultoni), which is such a pale green that it can actually appear white (or snowy). This was clearly not a snowy tree cricket.
The problem is, the best way to identify a tree cricket is to get a good look at the pattern of spots on the underside of the base of the antennae. Alas, I have no such view to look at, so I’ll have to settle for a general identification. The fact that I couldn’t identify this particular insect didn’t appear to have any effect on her, however.
The subfamily name Oecanthinae and the genus name Oecanthus mean “lives in flower,” and that is exactly where I found this female. She was easy to spot against the purple flowers of a Joe-Pye weed plant and docile enough to pose for photos. Unlike the pulsing chirps of field crickets, tree crickets have a drawn-out trill that can be easily overlooked unless you’re consciously listening for it. Males use these songs to attract females, and after mating, the females use those long ovipositors to lay eggs in the bark or stems of herbaceous plants. The favorite food items of tree crickets are aphids.
Autumn has technically begun, but the insects won’t give up until the cold weather kills off the adults. So get outside and see what wonderful curiosities you can find. Feel free to e-mail me any photos you may have to try and identify insects that give you trouble.
Bill Danielson has worked for the National Park Service, the US Forest Service, and the Massachusetts State Parks. He has been a professional writer and nature photographer for 19 years and he also teaches high school biology and physics. Visit www.speakingofnature.com for more information, or go to Speaking of Nature on Facebook.