what's this North American caterpillar? Identify caterpillar's here

This partner site of 'What's this caterpillar?' aims to identify the most common species of caterpillars found in North America. The site is set out in sections depicting those caterpillars that are smooth, knobbly, horned, fleshy, slug-like, hairy, tufty, bristled, spiny, those that feed within plants and those that build structures.
indicates a photo available. Check the album for new photos.
caterpillars smooth caterpillars knobbly caterpillars with horns caterpillars slug-like caterpillars hairy caterpillars spiny caterpillars with bristles caterpillars feeder caterpillars builder caterpillars fleshy bristly tufty caterpillars
Grateful thanks to Troy Bartlett who has a fantastic image gallery and allows use of some here. Thanks also to L. Anness, Stuart Schwartz and Kevin Fuge who have allowed permission to use photographs. If I have used your photgraph and not credited you, please email me so I can make amends. If you wish to send photographs, please send them to JavaJane. They must not be copyrighted material, unless you own the copyright.
This is a free site. Created and constructed by JavaJane, a professional web developer, the site began in October 2002 and completed after months of hard work. Advice and identification given freely. If you have found this useful, please share with everyone in the message forum. You can donate money to charity if you feel inclined!
My knowledge of North American species is limited as I am in the UK. For reference I used the Peterson First Guide to North American caterpillars. Not all caterpillars are pictured, your photographs needed.

Caterpillars seen this month in the U.S : spinky oak slug caterpillar Hickory Horned Devil
Photographs (submissions by visitors) Now in categories for easy use.
Hairy/Spiny caterpillars (195 images)
Smooth/Bumpy caterpillars (125 images)
Hawk (Sphinx) moths (79 images)
Can you name the unknown? Please look here to see if your caterpillar is pictured as the most commonly found ones are featured. Photographs emailed will be added to the gallery. Kudos to the photographers here. These photos are copyrighted, please do not take them for your own website.
Fact: The most commonly requested ID in the US is for Cecropia moths, Tobacco Hornworms and Black Swallowtails.
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Credits (photographers please let me know if you wish to be credited) Many thanks to the artists who have permitted use of their photogrpahs for this web site.
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