At first sight this weird caterpillar looks like an odd gum wrapper with its bright green color and four brown horns sticking out of the ends. It actually sticks to objects like gum, but there the similarity ends. This is more of a Harry Potter type of beast, it looks fun, but it is nasty. As much as you are tempted to poke it right in the middle, do not. If you push down on the middle, both ends of the caterpillar will bend in and get you. This happens to be one of the most poisonous of the caterpillars found in Eastern North America. It has venomous spines that are hollow and will stick into your skin leading to nasty reactions in your skin and body.
Found all the way up and down the East Coast, and across to Kansas, this caterpillar can eat a whole range of landscape plants. Often you can identify an insect pest by what you find it feeding on in your garden; not so the Saddleback Slug Caterpillar, as it feeds on all kinds of plants. As a gardener the primary danger is not to your plants but really to you. No wonder my dermatologists said to me, as she looked over her glasses at me, “really is it too much trouble to take the extra five seconds to put on a pair of gardening gloves”. Maybe this time I will listen to her?
Well, it LOOKS pretty anyway…
I found two of these guys in my yard in Southern Maryland recently; I suppose the first was a younger instar, as it had no spines and no protuberances other than four vestigial horns. It was pretty smooth all over, with no sign of the leg-like protrusions, false eye spots, or facial wrinkles. In fact, I couldn’t tell one end from the other, but it DID have the distinctive saddle-spot.
The second one looked pretty much like your pictures.
Just how serious IS their venom anyway?