In my previous post, I wrote about some yellow-striped armyworm caterpillars (Spodoptera ornithogalli) I’d brought home to raise.
Many caterpillars have beautiful markings, and this one was no exception. I didn’t notice this pretty geometric design on the dorsal side until the last instar.
There’s sometimes a bit of a challenge in identifying the species of a caterpillar because they can look very different depending on their life stage. Sometimes they’ll have completely different patterns in their early instars than they do in later instars, after molting several times. And my primary field guide doesn’t usually show more than one, or maybe two, instars for each species. So I have to consult multiple sources to confirm an identification; usually one or more of Mississippi State University’s “Moth Photographers Group,” BugGuide.net, or various Facebook groups like Mothing Ohio, Butterflying Ohio, or Caterpillars Ohio.
I didn’t know what to expect as far as how or when they would pupate, but it turned out I didn’t have to wait long to find out. On the morning of August 23, I discovered a little brown pellet lying on the bottom of the enclosure and a shriveled up exoskeleton beside it.
It surprised me because I’d thought they would need to hang from a stick or dig under some soil or something. I also thought a moth cocoon would be hairy or have a rough texture, so this smooth, shiny capsule intrigued me. (Correction: thanks to a kind reader I know that this isn’t a cocoon at all, but the actual pupal form of the moth.) I moved it into a separate little container, placed it on the kitchen counter, and waited for the others to pupate.
In the meantime, my research told me that this species would not overwinter in this form, but would instead emerge as an adult moth in only 9-22 days. That was exciting, because the idea of waiting all winter long to see its adult form seemed rather anticlimactic, after all the drama of finding it, identifying it, and then seeing it pupate.
So I marked September 1 as the first possible date of emergence. That day came and went. As did September 2. Then, at 7:00 on the morning of September 3, I was awakened by an unusual noise. My cat Sam and I both jumped out of bed and ran to the kitchen. We found Sophie on the counter pawing at the little container — which now had a moth fluttering around inside! So he only spent 11 days as a pupa.
The photos came out pretty dark, so I lightened this one to show his beautiful patterning:
I say this often, but it bears repeating: You will be amazed when you take the time to look closely at anything in nature. There’s so much hidden beauty right under our noses every day! My camera’s macro lens is one of my prized possessions; it changed my life by opening up a whole new world to me.
It may seem silly, but I was bursting with “parental pride” at having raised him from caterpillar to adult moth. It wasn’t quite as exciting as the first time I raised a monarch butterfly, but it was still enough to make me smile when I was barely awake enough to see what he looked like. This guy was quite agitated in his container and I had concerns that he would damage his wings, so I took a few photos as quickly as I could, and then placed his container in the garden under the sheltering leaves of a large hosta. I often find moths hiding there during the day, so I thought that would be a good place for him to hang out until he was ready to explore his new world.
If there are any farmers reading this, they might be annoyed that I raised this insect because it’s considered an agricultural “pest” and is a frequent target of crop pesticides. I guess that would be a fair point, but I also think that it was a great learning experience for me and it’s not like I’m raising bunches of them. In fact, only one of the armyworm caterpillars I found survived to adulthood. And I’m sharing what I learned too, so the educational value of raising this single moth is multiplied.
Also, I read in Caterpillars of Eastern North America (Wagner, 2005) that the adult moths of this species migrate here from the southern U.S. in the spring. They can have several broods throughout the summer, but they can’t survive the winter up here. Wagner doesn’t mention the adults migrating south again in fall, so does that mean that any of them that are here in the winter will perish and our population will get replenished in the spring when new adults migrate here? I’d still like to know the answer to that.
Having said all that, it’s been quite rewarding to successfully raise a moth for the first time. The Speyer’s cucullia caterpillars I showed in my previous post have burrowed into the soil already; if all goes well they’ll emerge in the spring. I’m continuing to raise the polyphemus moth caterpillars I mentioned previously too. They seem to be growing much more slowly than I’m used to seeing with monarch caterpillars.
And just a couple days ago my friend Annie gave me four black swallowtail caterpillars from her garden. That’s yet another new species for me, but I’ve already noticed that these butterfly caterpillars are growing much faster than the moth caterpillars. I wonder if it’s generally true that moth caterpillars grow slower than butterfly caterpillars; that sounds like something I should add to my list of winter research projects.
In the next couple of weeks I’ll have a few monarch butterflies emerging, and then I’ll look forward to releasing my very first black swallowtail butterflies. I can’t wait!