Currently viewing the category: "Inchworms"

15 Pages of Caterpillars… No Luck
Hey Bugman,
I searched your 15 pages of caterpillars frontwards, backwards and sideways trying to figure out who I captured on camera a couple of years ago in Peachtree, Georgia. Maybe this is something common that’s just in a different instar than a pic you have posted?  Whatever the case, I thought you might be interested.
Jim Olsson
Cheboygan, MI

Inchworm camouflaged with bits of plants

Inchworm camouflaged with bits of plants

Hi Jim,
We actually do have several images of Inchworms, the caterpillars of the Geometrid Moths, that have camouflaged themselves with plant material.  BugGuide has specimens from the genus Synchlora that exhibit this unusual behavior.  The appearance of the plant parts on your specimen is resulting in the appearance.  Other than the choice of plant material, there is one image on BugGuide that looks very much like your caterpillar.  Inchworms are also called Spanworms.

Unknown caterpillar – Flagstaff, AZ, U.S.A.
I am hopeful that you’ll be able to help me with the caterpillar in the attached photos. These were taken on April 26, 2008 in my yard in Flagstaff, AZ, U.S. Flagstaff is in the mountains of Arizona at an elevation of about 7000 feet (a bit over 2130 meters – I think). After perusing your letters on caterpillars (I am amazed at your knowledge), I am wondering if it is an early instar of a Parnassian species? However, my “Butterflies of Arizona” does not list any Parnassians. And, while the National Audubon “Field Guide to North American Butterflies” does list a few, the descriptions of the caterpillars don’t seem to match. This particular caterpillar appears to be white with black, longitudinal stripes, and yellow spots along the sides. It was on a Penstemon, which is listed (in the Audubon book) as a host plant for the Arachne Checkerspot, but the caterpillar description doesn’t seem to match up. I’m at a bit of a loss … Thank you for a wonderful site, and thank you in advance for any assistance.
John Ellison,
Flagstaff, AZ, U.S.A

Hi John,
We have to come clean and say we just don’t know for sure. Based on the absence of most typical pairs of prolegs, we believe this is a Spanworm or Inchworm in the family Geometridae, but we cannot locate a good match on BugGuide.

Update May 25, 2014:  Meris paradoxa
Thanks to an identification request we received today, we were able to identify the new request as well as the long unidentified posting from our archives as
Meris paradoxa, an Inchworm with no common name.


Happy new year. 2 queries please, the spider had immobilised the bee, is that its tongue sticking out and what do bees use such a large tongue for? The caterpillar is on a flowering gum in my garden in Queensland and i wondered if you could identify it for me. Thanking you,
dawn lewis

Hi Dawn,
Bees have long tongues to lap up nectar from plants. Your caterpillar seems to be some species of Inch Worm or Spanworm in the family Geometridae. We found an awesome webpage of Australian Geometridae, but had no luck identifying your caterpillar exactly. Caterpillars in this family are also known as Loopers, Measuring Worms and Twig Caterpillars.

Update: (01/04/2008) Unknown owlet moth from Australia
Dear Daniel,
Going on my own observations, it looks very much like the caterpillar of the Hakea or Pink-bellied Moth, Oenochroma vinaria, posted on WTB on 11/11/07. The caterpillar has small white dots over its body and also some yellow larger dots along the back. There are two “horns” just behind the head. When disturbed, the caterpillar rears up, showing its horns more clearly. When at rest, it is well camouflaged, looking just like a brown stick. And a Happy New Year to you and all WTB readers, also.

beautiful fern-like inchworm found in Tennessee
Hello whatsthatbug! Thought i’d add to the bizarre inchworm pictures with these snapshots of a strange brown fern frond i saw waving in the breeze-less air of Franklin, Tennessee this September. Upon closer inspection, it was of course this lovely creature. I’ve attempted to look up caterpillars of tennessee, but haven’t found this guy. Any help, or a point in the right research direction would be appreciated! thank you for the lovely site!

Hi JD,
We quickly identified this inchworm as a Showy Emerald, Dichorda iridaria by using BugGuide.

Inchworm/Oak Besma? Butterfly?
Hello again What’s That Bug.
I noticed on the Caterpiller page you have the Inchworm/Oak Besma identification, but the picture is hard to see. I’d like to contribute my own. Again, these are found in my backyard in central Indiana. I have also included a picture of a butterfly I found at the Gatlinburg Ripley’s Believe It Or Not! Aquarium in Tennessee. I searched the site, but I’m unsure as the type of butterfly it is. Can you help?
Heather Burdette

Hi Heather,
Your unidentified butterfly is a Tiger Swallowtail, Papilio glaucus, but a black morph. According to BugGuide: “A dark phase occurs in females through much of range, esepcially in southern states. The stripes are still faintly visible from some angles. The black females may be distinguished from other swallowtails from below, by the absence of the band of orange spots on the hind wing seen on Black and Spicebush Swallowtails, and lack of iridescent blue of Pipevine Swallowtails. ” We are not entirely sure your Inchworm is an Oak Besma. It appears to be feeding on a maple leaf and there are other Geometrid Caterpillars that look very similar. Bugguide lists the food plants as: “Oak, elm, poplar, willows, and white spruce.” So our verdict is maybe yes and maybe no.

Big Ugly Worm
Hi. We have been enjoying your site very much since we discovered it a few days ago. Now we have found a weird ugly bug we would like to have identified. We live in northeastern PA. Our area is heavily woodedbut we are not near water. This THING was seen “inching” along on the concrete pad by my pigeon lofts. It moves by bending itself up into a bow shape, then reaching out with the front. It’s like an inchworm, only much bigger and uglier. It has 4 caterpiller-like feet (my son says they are pseudopods) on the back end, and about 8 claw-like feet on the front. It SCARED us! What is it?
Thank you,
Sue and David

Hi Sue and David,
You can stop being scared of your Spanworm or Inchworm, one of the Geometrid Caterpillars. They are very difficult to positively identify. Our best guess is the Oak Besma, Besma quercivoraria, which eats a wide variety of forest trees besides oaks including conifers. There are conspicuous wartlike swellings that help it to mimic a twig that has had the leaves drop off, especially when the caterpillar rests by streching straight out at an oblique angle. Here is a page full of Geometrid Caterpillars from the Caterpillars of Eastern Forests website.