megathymus yuccae

from The Collaborative International Dictionary of English v.0.48

Yucca borer \Yuc"ca bor`er\
   (a) A California boring weevil ({Yuccaborus frontalis}).
   (b) A large mothlike butterfly ({Megathymus yuccae}) of the
       family {Megatimidae}, whose larva bores in yucca roots.
       [Webster 1913 Suppl.]