It look to me like the larvae of the black swallowtail butterfly:
http://www.npwrc.usgs.gov/resource/d...usa/pa/895.htm

although they are usually found on dill and parsley. I am always pleased to
spot these, and gladly sacrifice a bit of vegetation to help propagate the
species. They are seldom present in large numbers, and do little damage in
the overall scheme of things. Butterfly numbers in general are declining
due to indiscriminate pesticide use, so I try to do my part in creating
mini-ecosystems for the adults and the larvae.

Actually, I'm jealous...I haven't seen any of these guys yet this year,
probably due to last year's drought and this year's cold wet spring, and I
miss them. The only visitors I have to my butterfly bushes are the
ubiquitous cabbage whites.

Cheers,
Sue

"Jim Carter" wrote in message
...
The Wife (TM) has been finding green caterpillars munching on the leaves
of her
beans. Can anyone identify what this caterpillar was, just before She
whacked
it? It was about 1/2 inch long. Is there a Weapon of Mass Destruction
that
will kill any that are still lurking? We are in Eastern Ontario. Here is
a URL
where you may see the beast:

http://web.ripnet.com/~jcarter/worm.html
--
Gardening Zones
Canada Zone 5a
United States Zone 3a
Near Ottawa, Ontario