Caterpillar “nesting” in closed Queen Anne’s Lace – not Black Swallowtail
September 17, 2009
Last week (Sept. 13, 3009), out of curiousity, I opened up some Queen Anne’s Lace “nests” – i.e., the closed cup-like shape that the blooms take as they go to seed. About 1/3 of the nests had one of these small caterpillars in it. They were usually resting on or underneath a small silk pad, slightly larger than their bodies. The “nests” were full of frass, and it felt as if a bit of silk was being used to help keep the cup of the bloom closed more tightly than those without caterpillars inhabiting them.
All searches of “caterpillar, Queen Anne’s Lace” bring up the black swallowtail, but none of them seem to mention this caterpillar.
The closest I’ve come to identifying it is a picture of a Nettle-Tap Moth caterpillar. The Nettle-Tap Moth is found in England, which is the same place that Queen Anne’s Lace originated from, so it’s not impossible that that’s what this is. However, I can find no mention of it as a host plant. The nettle (of course) is what’s always mentioned.
This must be a fairly common caterpillar if it’s so easy to find. Can you help me identify it? Thank you.
I’m enclosing closeups of two caterpillars and one larger view which includes my thumbnail, for scale. The first caterpillar is smaller than the second, and may be an earlier instar.
Thank you for your wonderful site!!!
Valerie
Lake Forest, IL

Parsnip Webworm

Parsnip Webworm

“Caterpillar “nesting” in Queen Anne’s Lace – NOT a Black Swallowtail
September 18, 2009
By searching “black spotted, caterpillar”, I found a caterpillar that has the same spot pattern my unknown one, but it can’t be right. It’s a Pickleworm (!). The only problem is that it’s a southern US caterpillar, and I live in Illinois. Apparently they don’t survive cold winters and they like squash, canteloupe, and cucumbers. No mention of Queen Anne’s Lace, but they do tend to go for the blossoms of their food plants.
Wait, wait… in some years they may reach Michigan. Hmmm…
Here’s a link with info: http://entomology.ifas.ufl.edu/creatures/veg/pickleworm.htm
I’m attaching the photo that does resemble the caterpillar I found.
Valerie
Lake Forest

Hi Valerie,
This is a Parsnip Webworm, Depressaria pastinacella, which you can see on BugGuide.  We are not posting the found photo of the Pickleworm since you did not take it and since it is not your species.

Parsnip Webworm

Parsnip Webworm

Fantastic, and, considering the host plant, it makes a lot of sense.  Great work, and thank  you so very much!
I’m sorry, I didn’t expected you to print the photo I linked to; I was just including it in case it would help with the identification  Thank you for your quick and perfect ID.  Mystery solved!
Also, enjoying all the reactions to Ichneumons.  I saw my first one last year during a bicycle ride in the woods, and it certainly freaked me out at first.  Amazing that they can get those whip-thin ovipositors through the wood.
Many thanks from Illinois,
Valerie

Update and Correction
Caterpillar “nesting” in closed Queen Anne’s Lace – not Parsnip Webworm either (Part III)
September 25, 2009
Turns out the caterpillar in question isn’t exactly a Parsnip Webworm (as it was identiied in the Sept. 19, 2009 posting).
I wrote to May Berenbaum, an entomologist at University of Illinois who studies Parsnip Webworms, to ask her why she didn’t have Queen Anne’s Lace listed as a host plant in her papers, since that’s what I found this caterpillar on.
Turns out there’s “a new moth in town”, so to speak. Only recently identified as a newcomer to America, it is the Sitochroa Paelalis. Its larvae, of which there are few pics on the web (http://ukmoths.org.uk/show.php?id=3280), are only distinguishable from the Parsnip Webworm by experts, but the according to Dr. Berenbaum, the host plant and the time of year (most Parsnip Webworms finish their development by July, according to Dr. Berenbaum) help determine its identity.
Apparently it’s been spotted in Michigan, Indiana, and Illinois. I’ll try submitting some photos of the larvae to the bugguide to round out their collection, if they’ll take it (http://bugguide.net/index.php?q=search&keys=sitochroa+palealis).
I can’t thank you enough for this site and your help; I’d never have gotten to the right answer without you, and I’d never have gotten to write to a famous entomologist!
(p.s. You just know you’re begging for a smart aleck answer when you’re asked to prove your a human being by giving the color of snow! Didn’t you guys ever listen to Frank Zappa? *G*)
Valerie
Lake Forest, IL

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