The Collaborative International Dictionary
Megathymus yuccae
Yucca borer \Yuc"ca bor`er\
A California boring weevil ( Yuccaborus frontalis).
A large mothlike butterfly ( Megathymus yucc[ae]) of the family Megatimid[ae], whose larva bores in yucca roots.
Wikipedia
Megathymus yuccae
Megathymus yuccae, the yucca giant-skipper, is a rare early season butterfly that is widespread across the southern United States. It belongs in the family Hesperiidae, subfamily Megathyminae.