I don't know if this is a bug or a worm. Found under the soil while removing a sickly rhododendron. The head wiggles when I try to touch its body.
CLOSED: What is this reddish brown "thingie"
Flapdoodle Minot, ND Apr 20, 2013
Well, it's actually a pupa, not a cocoon. The two families of moths whose pupae often are found in soil are Sphingidae (hawk moths) and Noctuidae (owlet moths).