rootworm

[ root-wurm, roo t- ]
/ ˈrutˌwɜrm, ˈrʊt- /

noun

the larva of any of several insects, as the cucumber beetle, that feeds on the roots of plants.
any of several nematodes, especially of the genus Heterodera, that puncture and feed in the roots of plants.

Origin of rootworm

First recorded in 1795–1805; root1 + worm