I'm happy to have someone confirm my Abbot's Sphinx. I'm still confused by the variations in the adults as displayed on the Abbot's Sphinx search of this site. This one in particular: http://bugguide.net/node/view/40777 is so different from the rest on that page and certainly different from any adult moths I've seen on our property. Incidentally, I have five pupas resulting from the cats picked from our Grape Valiant plant. They hopefully will overwinter in their bed of peat moss and potting soil so I can watch for them to eclose in the spring. Apparently I need to find the "Wagner" book....

The colors of the later instars can be quite different, but that knob is there on all of them.

As for the Wagner book, it's expensive, but I use it pretty often. Perhaps you can find one used.

The caterpillar stages were very interesting to watch as they changed so dramatically. What accounts for the difference in the appearance of the ADULT moths...the specimen I noted earlier on the search for Abbot's Sphinx, is totally different than all the rest of the photos, yet they had all been confirmed as Abbots' Sphinx moths. I Googled the Wagner book and found that it's one of the books I do have, just not with me. I didn't recognize the author's name. Thanks!

Keep in mind that most of the ID's here on BG are made by amateurs, just like me... and we do make errors, that's why there's that caveat when reading the site that the identifications may be "just plain wrong". That being said, the can be variations too. If you're uncertain about a particular ID, you can always post in the forum asking for confirmation and/or explanation of variation.
Nina