cochineal

1 a red dyestuff consisting of dried bodies of female cochineal insects

2 Mexican red scale insect that feeds on cacti; the source of a red dye [syn: cochineal insect, Dactylopius coccus]

English

Noun

1. A species of insect (Dactylopius coccus).
2. A vivid red dye made from the bodies of cochineal insects.

Synonyms

• E120 (dye)

Translations

Cochineal is the name of both crimson or carmine dye and the cochineal insect (Dactylopius coccus), a scale insect in the suborder Sternorrhyncha, from which the dye is derived. There are other species in the genus Dactylopius which can be used to produce cochineal extract, but they are extremely difficult to distinguish from D. coccus, even for expert taxonomists, and the latter scientific name (and the use of the term "cochineal insect") is therefore commonly used when one is actually referring to other biological species; suffice it to say that the reader should be aware that there is more than one cochineal insect. The primary biological distinctions between species are minor differences in host plant preferences, in addition to very different geographic distributions. D. coccus itself is native to tropical and subtropical South America and Mexico.

This type of insect, a primarily sessile parasite, lives on cacti from the genus Opuntia, feeding on moisture and nutrients in the cacti. The insect produces carminic acid which deters predation by other insects. Carminic acid can be extracted from the insect's body and eggs to make the dye. Cochineal is primarily used as a food colouring and for cosmetics.

After synthetic pigments and dyes such as alizarin were invented in the late 19th century, natural-dye production gradually diminished. However, current health concerns over artificial food additives have renewed the popularity of cochineal dyes, and the increased demand has made cultivation of the insect profitable again.

History

The cochineal dye was used by the Aztec and Maya peoples of Central and North America. Eleven cities conquered by Montezuma in the 15th century paid a yearly tribute of 2000 decorated cotton blankets and 40 bags of cochineal dye each. During the colonial period the production of cochineal (grana fina) grew rapidly. Produced almost exclusively in Oaxaca, Mexico by indigenous producers, cochineal became Mexico's second most valued export after silver. The dyestuff was consumed throughout Europe and was so highly prized that its price was regularly quoted on the London and Amsterdam Commodity Exchanges.

After the Mexican War of Independence in 1810–1821, the Mexican monopoly on cochineal came to an end. Large scale production of cochineal emerged especially in Guatemala and the Canary Islands. The demand for cochineal fell sharply with the appearance on the market of alizarin crimson and many other artificial dyes discovered in Europe in the middle of the 19th century, causing a significant financial shock in Spain as a major industry almost ceased to exist.

In recent years it has become commercially valuable again, though most consumers are unaware that the phrases "cochineal extract", "carmine", "crimson lake", "natural red 4", "C.I. 75470", "E120", or even "natural colouring" refer to a dye that is derived from an insect. One reason for its popularity is that, unlike many commercial synthetic red dyes, it is not toxic or carcinogenic. However, the dye can induce an anaphylactic shock reaction in a small number of people.

Biology

Cochineal insects are soft-bodied, flat, oval-shaped scale insects. The females, wingless and about 5 mm (0.2 in) long, cluster on cactus pads. They penetrate the cactus with their beak-like mouthparts and feed on its juices, remaining immobile. After mating, the fertilized female increases in size and gives birth to tiny nymphs. The nymphs secrete a waxy white substance over their bodies for protection from water and excessive sun. This substance makes the cochineal insect appear white or grey from the outside, though the body of the insect and its nymphs produces the red pigment, which makes the insides of the insect look dark purple. Adult males can be distinguished from females by their diminutive size and their wings.

It is in the nymph stage (also called the crawler stage) that the cochineal disperses. The juveniles move to a feeding spot and produce long wax filaments. Later they move to the edge of the cactus pad where the wind catches the wax filaments and carries the cochineals to a new host. These individuals establish feeding sites on the new host and produce a new generation of cochineals. Male nymphs feed on the cactus until they reach sexual maturity; when they mature they cannot feed at all and live only long enough to fertilize the eggs. They are therefore seldom observed. All of the host plants of cochineal colonies were identified as species of Opuntia including Opuntia amyclaea, O. atropes, O. cantabrigiensis, O. brasilienis, O. ficus-indica, O. fuliginosa, O. jaliscana, O. leucotricha, O. lindheimeri, O. microdasys, O. megacantha, O. pilifera, O. robusta, O. sarca, O. schikendantzii, O. stricta, O. streptacantha, and O. tomentosa.

Several natural enemies can reduce the population of the insect on its cacti hosts. Of all the predators, insects seem to be the most important group. Insects and their larvae such as pyralid moths (order Lepidoptera), which destroy the cactus, and predators such as lady bugs (Coleoptera), various Diptera (such as Syrphidae and Chamaemyiidae), lacewings (Neuroptera) and ants (Hymenoptera) have been identified, as well as numerous parasitic wasps. Many birds; human-commensal rodents, especially rats; and reptiles also prey on cochineal insects. In regions dependent on cochineal production, pest control measures have to be taken seriously. For small-scale cultivation manual methods of control have proved to be the most effective and safe. For large-scale cultivation advanced pest control methods have to be developed, including alternative bioinsecticides or traps with pheromones.

Dye

A deep crimson dye is extracted from the female cochineal insects. Cochineal is used to produce scarlet, orange and other red tints. The colouring comes from carminic acid. Cochineal extract's natural carminic-acid content is usually 19–22%.

Usage

Traditionally cochineal was used for colouring fabrics. During the colonial period, with the introduction of sheep to Latin America, the use of cochineal increased, as it provided the most intense colour and it set more firmly on woolen garments than on clothes made of materials of pre-Hispanic origin such as cotton, agave fibers and yucca fibers. Once the European market had discovered the qualities of this product, their demand for it increased dramatically. Carmine became strong competition for other colourants such as madder root, kermes, Polish cochineal, brazilwood, and Tyrian purple, as they were used for dyeing the clothes of kings, nobles and the clergy. It was also used for painting, handicrafts and tapestries. Sometimes carmine is labelled as E120. An unknown percentage of people have been found to have allergies to carmine, ranging from mild cases of hives to atrial fibrillation and anaphylactic shock. Carmine has been found to cause asthma in some people. The water-soluble form is used in alcoholic drinks with calcium carmine; the insoluble form is used in a wider variety of products. Together with ammonium carmine they can be found in meat, sausages, processed poultry products (meat products cannot be coloured in the United States unless they are labeled as such), surimi, marinades, alcoholic drinks, bakery products and toppings, cookies, desserts, icings, pie fillings, jams, preserves, gelatin desserts, juice beverages, varieties of cheddar cheese and other dairy products, sauces and sweets. The average human consumes one to two drops of carminic acid each year with food. A significant proportion of the insoluble carmine pigment produced is used in the cosmetics industry for hair- and skin-care products, lipsticks, face powders, rouges, and blushes. A bright red dye and the stain carmine used in microbiology is often made from the carmine extract, too. The pharmaceutical industry uses cochineal to colour pills and ointments.

See also

• Polish cochineal
• Kermes vermilio
• Crimson

References

Sources for the History of Cochineal

• Jeremy Baskes, Indians, Merchants and Markets: A Reinterpretation of the Repartimiento and Spanish-Indian Economic Relations in Colonial Oaxaca, 1750–1821, Stanford: Stanford University Press, 2000.
• Amy Butler Greenfield, A Perfect Red: Empire, Espionage, and the Quest for the Color of Desire, New York: Harper Collins Press, 2005.
• Brian Hamnett, Politics and Trade in Southern Mexico, 1750–1821, Cambridge: Cambridge University Press, 1971.
• David McCreary, Rural Guatemala 1760–1940, Stanford: Stanford University Press, 1996.
• R.A. Donkin, "Spanish Red: An Ethnogeographical Study of Cochineal and the Opuntia Cactus," Transactions of the American Philosophical Society v. 67, pt. 5.

External links