What is "billbugs"

Curculio \Cur*cu"li*o\ (k?r-r?"l?-?), n.; pl. Curculios (-?z). [L., a grain weevil.] (Zo["o]l.) One of a large group of beetles ( Rhynchophora) of many genera; -- called also weevils, snout beetles, billbeetles, and billbugs. Many of the species are very destructive, as the plum curculio, the corn, grain, and rice weevils, etc.

n. (plural of billbug English)