We’ve have found a couple of caterpillers and can’t seem to come up with ‘what they are’. Hoping you can help us out. The yellow and black ones were found on a really young birch (two feet… the birch not the caterpillers!) Now That would be amazing!! They seemed to be chomping happily away at the leaves, and would strike a tail up and curve it along their backside when alarmed, and would also exhibit this behaviour toward each other, but with more of a whipping action. This guys were about one inch in length and only a few milliimetres around. They seem to be hairless. … Both species were found Aug. 7th, 2008, in Spruce Grove, Alberta (just outside of Edmonton), and in sunny locations. We are wondering if we can relocate them on another more mature tree, if it is a native species, as they have set up house on newly planted trees and we don’t think the wee trees can support their eating habits! I’ve attached photos, and hopefully have included all important details, if not, just contact us! Happily birding,
Michelle & Curtis

Hi Michelle and Curtis,
The “caterpillars” you found on the birch are the Larvae of the Dusky Birch Sawfly, Croesus latitarsus. It is a common error to mistake Sawflies for Caterpillars. Sawflies are related to wasps.

What's That Bug? does not endorse extermination

I’m stumped! What’s this bug?!
Hi Bugman!
Thanks for such a fab site! I took these pictures of a beautiful moth yesterday in my backyard in Decatur, GA. It fluttered away shortly thereafter. I initially thought it might be a Cecropia Moth, but some of its markings are inconsistent with the pictures I’ve looked at: it is lacking the vivid body color, for example, and the white crescent shapes on the wings seem too small. I’ve poured over all your moth pictures and those on some other sites, but am still stumped! Can you help? Many, many thanks…keep doing what you do!
Tracy D. James
Decatur, GA

Hi Tracy,
This is a Tuliptree Silkmoth, Callosamia angulifera, and it the second example we have received today. The first was from Virginia.

Ichneumon Species-New Find!
In addition to the email i sent earlier, i hope you received it. I was out taking more pics of bugs today, in my yard in Houston, Texas and i happened to catch a strange little, very little, bug hitching a ride on an Ichneumons antennae. I thought it was just a piece of skin or something while taking pics. I didn’t notice the little bug til i got them on the computer. What is this lil bug?
Tracy Palmer

Hi Tracy,
It takes quite some time to plod through all of a given day’s emails, and many do not get read. This is a marvelous set of images. They depict a Pseudoscorpion hitching a ride, a practice known as Phoresy, on an Ichneumon in the genus Megarhyssa. Because so many people find Pseudoscorpions in their homes, we have devoted an entire page to them.

What's That Bug? does not endorse extermination

Denver Buzzbomb!!!
We keep finding these little “buzzbombs” in our basement. Almost every day there is a new one trying to wreck the place. I think they might be some kind of ground bee, but I’m not sure. I can’t find anything quite like them on your site. They look like Tachinid flies, but their head is much smaller and located underneath their body instead of at the front. He’s an incredibly ungraceful flier, and spends most of his time in the house trying to get off his back. I cooled him down in the refrigerator to photograph him, and to warm up, he would buzz like a jet engine winding up. They are some of the strangest flies I’ve ever seen in Colorado. Thanks for your time.
Ryan Langan

Hi Ryan,
Interestingly, it seems like you arrived at the correct answer when you wrote: “… flies, but their head is much smaller … .” This looks to us like a Small Headed Fly in the family Acroceridae, and of the photos on BugGuide, it looks closest to Pterodontia flavipes or another member of the genus. We will try to contact Eric Eaton to get another opinion.

Update: (08/10/2008)
Hi, Daniel:
Yes, it is indeed a small-headed fly! Great call! Not sure of the genus, though. As larvae they are parasitic on spiders.

what is this caterpillar/cocoon
Hi. I have had these weird things all summer invading the pyracantha bush. (However you spell that) They mostly hang, but occasionally they will be crawling around dragging there home with them. Very curious, can you identify it? Thanks.

Hi Stephanie,
Once again we are not enforcing our threat to immediately trash all letters without locations, but only because in the interest of our readership, we feel you photos demonstrate an important documentation. These are Bagworms in the family Psychidae. Bagworms are caterpillars and pupae of moths. The caterpillars feed on a variety of plants, cedar, juniper and arborvitae being a favorite hosts, but pyracantha is also listed as a host. Bagworms construct bags from the leaves and twigs of their host plants, and we are amazed to see your photos of bags costructed of Pyracantha berries. We haven’t located another image online demonstrating the use of Pyracantha berries in the bag construction, but we just conducted a quick search.

So Sorry about not mentioning my location. I must have missed that threat somewhere on your page. I was just so excited to find someone who might know what it was. We are located in Midwest City, Oklahoma. This is just east of Oklahoma City. Thanks for the info.

Colorful flying thing….
Hey Bugman,
I found a rather interesting bug, well a colorful one anyways, while on a hike in Irvine, California. I was wondering if you could help me identify it. I have two pictures, both are a little out of focus, but it should still be pretty visible. It was actually quite large, I would say close to the size of a finger (length-wise anyways). I apologize if you’ve identified it before. I tried looking through your site, but there are way too many bugs already here, and I hardly know what category to look under anyways. Thanks for your help. Cheers,

Hi Janek,
This is a wasp in the genus Pepsis, commonly called a Tarantula Hawk.