The most direct way is to flick them into soapy water.

If they're half-grown or less, BT will work; it's sold under various brandnames among them Dipel, Thuricide & Caterpillar Attack.

There's a potential glitch in using BT beyond the fact that they're too "old." If the "caterpillars are instead sawaflfies, Bt won't work.

The 2 insects look *very* similar. Any chance of posting an image or two?

If not, the soapy water trick works for both.

My guess is that you're seeing the willow sawfly. Click on the link below for an image to compare. If not, you'll need to let us see a picture in order for a good ID.

If it is the sawfly, do not use the Bt products, as Jean mentioned. They will not work and you shouldn't apply the stuff indiscriminately. Let us know!

Here is a link that might be useful:

I'm having the exact same problem!

I have noticed them twice now! Each time I inspected the whole tree thoroughly, and found a small group of these "bugs" at the end of a branch eating away, starting with the leafs at the end of the branch, and working their way towards the tree trunk. When I grab the branch to inspect it, I notice the little caterpillar-looking things have 2 or 3 legs on each side of their body, and only on the from 1/4 of their bodies. They seem attached to the leaf with their short legs and then they lift up the back 3/4 of their bodies in the air. What are these things and how do I get rid of them?

Each time I have cut the small branch about 3 inches back from where they were and have thrown them in the garbage both times. What is a more permanent solution and where are they coming from?

Any info would be greatly appreciated.

Jen from the northern, Washington State coast.

farmer, you'll have to either submit an image or compare to the picture in the link attached from last year. We can't tell you how to control them or where they are coming from without some more information from you.

Pruning the plants to get rid of these seems a bit drastic.

You were correct... They were actually willow sawfly's and not a caterpillar. Sure enough, these little buggers were back this past summer. This year I used diatemacious earth to help control them. I had to do about 3 applications with in a 3 week span but it kept them from eating away my willow. Thanks for all your advice!