Oak Slug Caterpillar

Description:

Pale green with 2 pairs of horn like projections with black spines, and 3 pairs of projections in the rear, with shorter projections in between. Can have Orange, Red, or Yellow coloration in the body.

Habitat:

Found on an unknown plant in the scrubby woods between two old fields.

Notes:

Last photo is of the unknown plant this was found on. It was wrapped in the leaf of one of them, secured with silk of some sort. I have been told by friends that this is a "stinging" type of caterpillar...would love to know if this is true, but I do not handle caterpillars usually.