slugworm

from The Century Dictionary.

• noun One of the slimy slug-like larvæ of the saw-flies of the genus Selandria and allied genera; specifically, the larva of S. cerasi.

from the GNU version of the Collaborative International Dictionary of English.

• noun (Zoöl.) Any caterpillar which has the general appearance of a slug, as do those of certain moths belonging to Limacodes and allied genera, and those of certain sawflies.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun Any caterpillar which has the general appearance of a slug.