Ecology, use, and management of cochineal insects (Hemiptera: Dactylopiidae)

Abstract

Cochineal insects, genus, Dactylopius, are scale insects that suck fluids from many or most species of prickly pear cacti (Opuntia spp.) and a few related cactus species from the southwestern United States, Mexico, and temperate South America. These insects have a typical scale life history pattern with mobile first instar nymphs (“crawlers”) and winged adult males and wingless, sessile females. Cochineal insects are best known for producing carminic acid, a red glucosidal anthraquinone, which deters most invertebrate predators and can be extracted from the insects and mixed with alum or calcium salts to make a bright red dye known as carmine or cochineal, leading to the early domestication of this insect for dye production. This dye was widely used by the Aztec, Maya, and Inca cultures to dye fabrics, manuscripts, and other materials and became the second most valuable export from the New World during the Colonial Period. Fabrics dyed with cochineal became a symbol of wealth. The dye was notable for coloring the robes of Catholic cardinals, British “redcoats” and even the red stripes of early US flags. Modern uses include dyes for textiles, food coloring, and cosmetics. Cochineal insects have been transported worldwide for dye production, but also for biocontrol of invasive prickly pear cacti. However, where prickly pears were introduced for food or fodder, these insects often become pests, occasionally requiring control. Several tactics are available for managing cochineal insects, including planting of resistant prickly pear varieties, mechanical removal, introduction of specialist predators, and some insecticides.