Either of two blue leaf beetles, Phaedon cochleariae and P. armoraciae, which are destructive to mustard and other plants of the family Brassicaceae (Cruciferae).
Origin
Late 19th century; earliest use found in The Standard.
Definition of mustard beetle in US English:
mustard beetle
noun
Either of two blue leaf beetles, Phaedon cochleariae and P. armoraciae, which are destructive to mustard and other plants of the family Brassicaceae (Cruciferae).
Origin
Late 19th century; earliest use found in The Standard.