cochineal insect

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun Any of several scale insects of the family Dactylopiidae, especially Dactylopius coccus, that feed on prickly pear cacti and range from the southwest United States to Central America.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun Mexican red scale insect that feeds on cacti; the source of a red dye