Buckeye Petiole Borer

Back in May, I posted a mystery I had encountered a week earlier involving caterpillars boring in petioles of Ohio buckeye (Aesculus glabra). I’ll copy and paste the relevant photos below, but for explanations you can check out the original post.

That last photo was taken on April 27. On May 11, a larva appeared outside of the petioles, and its bloated, stiff-legged appearance made me wonder whether it was parasitized by some kind of mummy-wasp larva.

Two days later, it had become darker and more hardened, which seemed like progress toward rearing an adult wasp…

…but nothing ever came of it. As you can see, things were getting pretty moldy in the rearing vials. So I was surprised and delighted when a healthy-looking moth pupa suddenly appeared on May 24.

A couple of other pupae appeared, and on June 2 the first of two adult moths emerged.

As I had mentioned in a comment on my original post, my prime suspect was Proteoteras aesculana (Tortricidae), which has been given the common name of “maple twig borer,” but whose Latin name is clearly a reference to its having originally been found on buckeye (Aesculus). I checked photos of adults, and the wing pattern and coloring seemed similar, but I was concerned that my moths lacked the prominent wing tufts that are present on all of the examples on BugGuide.

Recently, I sent a few reared moths to tortricid specialist John Brown at the Smithsonian. Yesterday, he reported back with the identifications, and he listed the above moth as a female P. aesculana. However, a little while later he wrote back and said: “I was putting your specimens in the collection when it occurred to me that your Proteoteras aesculana may be Zeiraphera claypoleana. I’ll dissect it and see what the tail says.” This morning, he reported: “The female Proteoteras is indeed Zeiraphera claypoleana.”

Zeiraphera claypoleana, it turns out, has been given the common name “buckeye petiole borer.” According to BugGuide, it was originally described from Ohio, and Ohio buckeye was given as the host plant. So clearly I haven’t discovered anything new here (in contrast to another of the moths John identified, which apparently had never been reared before, and is the solution to another one of my Monthly Mysteries. But I’ll save that for another time).

One curious thing I just noticed, when picking out photos, is that the other moth I reared from the buckeye petioles (which I did not send to John) looks totally different:

With that dark patch on its back, it looks much more like the one example of this species that is currently on BugGuide. Somehow, without magnification, the two pinned and spread specimens didn’t appear strikingly different, so I didn’t give much thought to which one I should send out for identification. The pinned example on Moth Photographers Group doesn’t seem to have the dark patch, so I guess this is just a very variable species.