Is it tiny? It looks like a Lycaenidae caterpillar. Perhaps a summer azure (Celastrina neglecta)? They lay eggs on a variety of flower buds and eat the flowers. However, I cannot find any pictures of one to confirm.
-Elisabeth

Well we don't hardly get them those far south but I was reviewing cats in my butter fly book and I believe the one you have pictured there is one called the "Common Blue" way north of my region. But I could be wrong...

From the pictures in my book, I was guessing Common Blue also. Size would help to determine id.

Which blue do you mean? I don't have my butterfly books in front of me and am not aware of a common blue other than Polyommatus icarus, which is a European species.

Another guess would be a gray hairstreak, Stymon melinus. Here is what Wagner's "Caterpillars of Eastern North America" Says;

"Often green with oblique dark reen line above each spiracle"

"Pale subspiracular stripe runs from T3-A7"

"Setae over dorsum rather long for a lycaenid, nearly half as long as a segment that bears them. Setae from subdorsal selling often with minute dark bases."

Also the Eastern Tailed blue, Everes comyntas;

"Integument with conspicuous peppering of small white (or sometimes black)star shaped setae (best viewed with lens). Usually with darkened middorsal line and prominent subspiracular stripe"

"Setae prominent, longest hairs about one-third length of segment that bears them. Larva scarecly exceeding 1 cm." Gray Hairstreak (Strymon melinus) caterpillars lack the star-shaped setae."

My guess is gray hairstreak, but whatever s/he is, s/he is cute!

-Elisabeth

Could it possibly be the Eastern Tailed Blue?
http://www.buglifecycle.com/?p=380

I second Elisabeth: Lycaenid of some sort, and the host plant and location narrow it down to either Gray Hairstreak or Eastern Tailed Blue. The Summer Azure eats a lot of different things, but I don't thing legumes are among them.

Here's a promising caterpillar gallery: http://www.pbase.com/tmurray74/butterfly_caterpillars

I think it is probably a Gray Hairstreak. What's great about this CD-ROM (Butterflies of North America...Scott) is that it has pictures of eggs, cats, and adults, plus natural history info. Gray Hairstreaks use Cassia (Senna). But, there's always a new butterfly host plant that's not cataloged.

Here is a link that might be useful: Species Strymon melinus - Gray Hairstreak (Caterpillar Pictures from the Bug Guide)

Bob,

This is a hairstreak larva. Because of the time of year and fabaceous host, it must be Gray Hairstreak (Strymon melinus).

David

PS - Lovely shots by the way.