Korean Mystery Caterpillar
May 31, 2010
Dear Bugman (men/women),
I’m a kindergarten teacher in Seoul, South Korea. My walk to work every morning takes me down a mountain (part of the range that drops down into Northern Seoul) and I make it a habit to photograph and (when possible) pick up interesting things for my students on the way. We already have a garden snail in a terrarium in our classroom and he’s been a great success. Just this morning (May 31st) I was walking down the hill as usual and nearly smushed something green. I stopped and found a caterpillar on the road. He’s – hang on, let me measure him – three centimeters long, a beautiful bright green, with a yellow-white lateral stripe on each side, and a white stripe down his back. He has tiny white spots all over except along the lateral lines, where the dots are white inside with a ring of black surrounding. He has a single posterior horn that looks more like a rose thorn than a long thin antler; the horn has white stripes running up to the tip (one following the dorsal st ripe and two on either side for a total of six). He’s got two legs under the horn, then a eight in the middle, and what seem to be six smaller ones under his face. He’s soft and velvety to the touch and completely harmless.
I sure hope that’s a detailed enough description for you. I’d like to keep him in the classroom throughout his metamorphosis if I possibly can, but first of all I have to figure out what kind of plants he likes to eat – so far he’s not been interested in the local greenery I’ve plucked (lilac leaves, leaves from the azaleas that are all over the place, some random other stuff). What IS this little guy? Is he going to do well in a terrarium? And by some miracle, do you know what he’d like to eat?
Thanks a bunch!
Miss Sandra and the Yellow Canary classroom
Bukan-san mountain region, Seoul, South Korea

Copper Underwing Caterpillar

Dear Miss Sandra,
First, we want to say that you sound like a wonderful teacher and that your class is fortunate that you have taken the initiative to teach your charges about the natural world.  Alas, we have struggled unsuccessfully to identify your Hornworm in the family Sphingidae in an effort to identify the food plant.  Hornworms are the caterpillars of Sphinx Moths or Hawkmoths.  They generally pupate underground, and it is possible that this caterpillar left its food plant to search for a good location to dig.  Providing some loose soil in the bottom of the terrariam may encourage him to dig underground to pupate.  Make sure the soil is not too wet nor too dry.  We have been searching the Sphingidae of the Eastern Palaearctic website, China section, in an attempt to identify the species, but China is a big country with many potential species.  Some moths pictured do not have images of caterpillars, and with some species, the life cycles and early stages are unknown.  Hopefully, one of our readers will be able to identify your species so that you can provide the necessary food.  The horn on your specimen is very unusual looking and should be able to provide a unique characteristic for identification purposes.

Copper Underwing Caterpillar

Correction thanks to Karl:  Underwing Caterpillar
June 1, 2010
Hi Daniel and Miss Sandra:
The unusual “horn” is actually more of a hump, and this caterpillar is an underwing moth (Noctuidae) not a hornworm (Sphingidae). It looks like a Copper Underwing (Amphipyra pyramidae) – other common names include Humped Green Fruitworm and Pyramidal Green Fruitworm. It’s a Palearctic species with a very wide distribution, including all of Europe and across central Eurasia to Korea and Japan, and the higher altitude regions of from North Africa to the northern Indian subcontinent. It appears to be present across North America as well but I suspect it has been introduced to that continent. There is an abundance of images on the internet (additional links below). A related species, A. perflua, has a similar distribution, including Korea, but I wasn’t able to find any images for comparison.

Dear Karl and Daniel,
Thank you so much for your information and assistance!  We had a great time in class looking at pictures of what our little friend will turn into.  We would have loved to watch his metamorphosis, but as we couldn’t entice him to enjoy any of our plant offerings, we let him go in our garden in the hopes that he would find his own way to something delicious.  You were all incredibly helpful – never have there been a group of five year olds so in love with bugs as my students, let me tell you.  I’ll be sure to take pictures of any copper underwings I run across!
Thanks again!

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