The larva of the anise swallowtail butterfly, Papilio zelicaon, which is a pest of plants of the family Apiaceae (Umbelliferae) in western North America.
Origin
Mid 19th century.
Definition of parsley caterpillar in US English:
parsley caterpillar
noun
US
The larva of the anise swallowtail butterfly, Papilio zelicaon, which is a pest of plants of the family Apiaceae (Umbelliferae) in western North America.