Cochineal

• 1. Introduction

  ›

  Cochineal is a scale insect, and it takes about 70,000 of them to make a single pound of its famous red dye. That is a staggering body count for a color. Yet this tiny parasite of cactus pads, known to science as Dactylopius coccus, once ranked among the most valuable goods crossing the Atlantic. Its price was posted on commodity exchanges. Its color dressed popes and soldiers. How did a speck clinging to a prickly pear end up shaping trade between continents? Why did people on three continents try to smuggle it, farm it, or stamp it out? And why, after nearly vanishing from the market, is it back in lipstick and food labels today?

  42756027

• 2. Life on the Pad

  ›

  A female cochineal is only about 5 mm long, wingless, and almost motionless for most of her life. She pushes beak-like mouthparts into a cactus pad, drinks its juices, and stays put unless something disturbs her. After mating she swells in size and gives birth to tiny nymphs. Those nymphs coat themselves in a white waxy layer that guards against water loss and harsh sun.

  The wax is why a living colony looks white or grey. Crush one of the insects, though, and the red pigment inside makes the body look dark purple. That pigment, carminic acid, also helps deter other insects from eating it.

  The young travel in a stage called the crawler. A juvenile finds a feeding spot and spins long wax filaments. Later it walks to the edge of the pad, where wind catches the filaments and carries it off to a fresh host.

  Males are a different story. They are much smaller than females and they have wings. A male nymph feeds on the cactus until it matures, and then it can no longer feed at all. It lives just long enough to fertilize eggs, which is why people rarely see one. Females typically outnumber males anyway.

  The cactus pays a price. About 200 species of Opuntia cactus are known, and cochineal can be raised on almost all of them, though Opuntia ficus-indica is the most common host. Heavy feeding can damage and even kill the plant.

  Cochineal has plenty of enemies. Pyralid moths, ladybugs, lacewings, ants, and numerous parasitic wasps all go after it, along with birds, reptiles, and rats. Insects seem to be the most important group of predators.

  Sorting out which cochineal is which is surprisingly hard. Other species in the genus Dactylopius yield the same kind of extract, and even expert taxonomists struggle to tell them apart from D. coccus. The long list of cacti recorded as its hosts probably reflects that confusion.

  234178

• 3. The Nopalry

  ›

  A nopal cactus farm built for cochineal has its own name: a nopalry. Farmers use one of two methods. In the traditional method, they plant cactus pads that already carry the insects, or they infest existing cacti, and then they harvest by hand.

  The controlled method relies on small baskets called Zapotec nests, set on the host cacti. Each basket holds clean, fertile females. The females crawl out, settle on the pad, and wait for the males to fertilize them.

  Either way, the insects need shelter from predators, cold, and rain. A full cycle lasts three months, and the cacti are held at a steady 27 degrees Celsius, or 81 degrees Fahrenheit. At the end, some of the new generation are left to breed. The rest are collected and dried for dye.

  The insects are picked at roughly 90 days of age. Gathering them is slow work, because each one must be knocked, brushed, or picked off the cactus and dropped into a bag. Small groups of collectors do the job and then sell their harvest to local processors or exporters.

  In regions that live off cochineal, pests get serious attention. On small plots, hand methods have proved the safest and most effective. Larger operations need more advanced tools, such as alternative bioinsecticides or traps baited with pheromones.

  This dependence on patient hand labor would later become the industry's greatest weakness.

  714184

• 4. Carmine Chemistry

  ›

  Workers who gather the females face an immediate problem, which is how to kill and preserve them. Boiling water, sunlight, steam, and the heat of an oven all work. Each method gives a different tint, and that is why commercial cochineal comes in varied shades. The insects must dry to about 30 percent of their original weight before they can be stored without rotting.

  The dried body of a female contains between 14 and 26 percent carminic acid. This molecule belongs to a family of anthraquinone dyes. Two other red insect dyes share that chemistry: kermes dye, colored by kermesic acid, and lac dye, colored by laccaic acids.

  Producers sell the result in two main forms. Cochineal extract is simply the raw insect bodies, dried and pulverized. Carmine is a more purified product. To make it, the powder is boiled in ammonia or a sodium carbonate solution, and the leftover solids are filtered out. Alum is then added to the clear liquid, and a red aluminium salt precipitates out.

  Iron is the enemy of a pure color, so its absence matters. Stannous chloride, citric acid, borax, or gelatin can be added to control how the precipitate forms. Add lime to the alum, and the shade turns toward purple.

  Artists wanted this red too, but it let them down. A dye dissolves in liquid, while a pigment is an insoluble powder suspended in a vehicle, and carmine behaves unpredictably as a pigment. Its solubility shifts with acidity. Red lake pigments in general had a reputation for instability by the 1400s.

  When cochineal lakes reached Europe, painters found that they faded. The paint turned brown in sunlight, though oil held up somewhat better than watercolor. The chemist Arthur Herbert Church put it bluntly: "Beautiful and rich as are the colours prepared from cochineal, not one of them should ever find a place upon the palette of the artist."

  By then the insect had been making color for people for well over a thousand years, and the first of them lived in the Americas.

  1516182933

• 5. Before the Spanish

  ›

  In the second century BC, people in Mesoamerica were already dyeing with cochineal. The Mixtec, Zapotec, Aztec, and Otomi all used it on fabric and on amate paper. By the thirteenth century, scribes were painting codices with it.

  Wild insects could be collected, but growers began raising cochineal in gardens. This semi-domesticated stock carried more dye, which made it more valuable to artists.

  The Matrícula de Tributos shows how much the Aztec state prized it. Eleven towns in the Oaxacan province of Coixtlahuaca, conquered by the Aztec Empire in the 15th century, each owed a yearly tribute of 2000 decorated cotton blankets and 40 bags of cochineal dye. One of them was Nochistlan, today Asuncion Nochixtlan. Its name comes from the Nahuatl word for cochineal, nocheztli.

  Far to the south, the Andes had their own tradition. People in Peru were making cochineal dyes for textiles early in the Middle Horizon period, which ran from 600 to 1000 CE. These cloths were often ceremonial, or made for rulers. The craft was well developed under the Nazca culture, and lovely cochineal-dyed weaving survives from the Moche and the Wari. Some of it came through in extremely dry parts of Peru.

  The dye clings best to animal fibers. Wool from alpacas and other camelids took it well, as did rabbit fur and feathers. Cotton and other plant fabrics accepted it less readily.

  The Florentine Codex, from the 16th century, shows the Aztec painters' skill with red. Technical analysis of its achiotl, a light red, reveals several layers of pigment that the naked eye cannot see. The method of layering mattered more than the finished shade. Bolder applications drew the eye, and weaker ones drew less attention. That suggests the Aztecs linked the intensity of a pigment with power and life.

  1921222526

• 6. Europe's Red Rush

  ›

  In the 1520s, cochineal began arriving in Spain from the New World. Europe already had a red. Kermes, made from scale insects that form galls on oaks around the Mediterranean, had colored cloth for centuries. It had served in ancient Egypt, Greece, Armenia, and the Near East. Polish cochineal and Armenian cochineal were also in use.

  The words themselves carry the story. English took cochineal from French cochenille, which came from Spanish cochinilla. That traces back to Latin coccinus and the Greek kokkinos, meaning scarlet. The Greek root referred to the oak galls, or to a dye made by crushing them. Some sources instead tie cochinilla to the wood louse, a diminutive of cochino, meaning pig.

  The Spanish conquest of the Aztec Empire in the 16th century let Spain exploit the new color quickly. Growers raised cochineal for export across Mesoamerica, especially in Tlaxcala, Puebla, and Oaxaca. When sheep arrived in Latin America, the dye found a new partner. It set more firmly on wool than on cotton, agave, or yucca fibers. Europeans came to prize the best grade, called grana fina.

  Carmine became the region's second-most-valuable export, behind silver. Its price was regularly quoted on the London and Amsterdam commodity exchanges, and Amsterdam began recording it in 1589. In the 17th century the dye was traded as far away as India.

  Power wore it. Spain and Italy regulated luxury colors and textiles, and cochineal dyed the clothes of kings, nobles, and clergy. In 1454, Pope Paul II changed the color of cardinals' robes from Cardinal's purple to a vibrant red. By 1558, those robes would have been made with American cochineal. In the 1600s it also gave English officers their distinctive scarlet uniforms. In oriental rugs, it almost completely displaced lac.

  Paying for all this was a system called Repartimiento de Mercancías. A trader lent money to producers in advance, with a call option to buy the harvest. Communities with a history of cochineal production show lower poverty rates and higher female literacy. They also have smaller indigenous populations.

  The trade changed how artists worked as well. A 16th century image of Moctezuma's death uses both indigenous and Spanish pigments. The scholar Diana Magaloni Kerpel reads the mix of cochineal and minium there as a sign of cultural transition and influence.

  Spain's grip on this red could not last, because other empires wanted a share.

  7560234445

• 7. Insects on the Move

  ›

  In 1777, the French botanist Nicolas-Joseph Thiéry de Menonville posed as a botanizing physician and smuggled cochineal insects and Opuntia pads to Saint Domingue. The collection failed to thrive and died out. The Mexican monopoly survived intact.

  A different scheme began in 1788, when Captain Arthur Phillip collected cochineal-infested plants in Brazil. He was on his way to found the first European settlement at Botany Bay, part of which is now Sydney. Spain and Portugal held a worldwide monopoly on the dye, and Britain wanted a source it controlled for its clothing and garment industries.

  The plan failed twice over. The Brazilian insects soon died, but the cacti flourished. They eventually overran about 100,000 square miles of eastern Australia. Control came only in the 1920s, when people deliberately introduced a South American moth, Cactoblastis cactorum, whose larvae feed on the cactus.

  The Mexican monopoly finally ended after the Mexican War of Independence, which ran from 1810 to 1821. Large-scale production grew up in Guatemala and the Canary Islands, and the insect was also cultivated in Spain and North Africa.

  Northern Ethiopia repeated the Australian mistake in the early 2000s. Communities there already ate the nopal pear, and carmine cochineal was introduced for farming. The company Foodsafe exported 2000 tons of dried cochineal over three years. Then a conflict of interest among the communities closed the business.

  The insect kept spreading anyway. Control efforts did not work, and by 2014 about 16,000 hectares of cactus land were infested.

  In South Africa, cochineal species were brought in on purpose as a biocontrol against invasive cacti. Dactylopius insects live on prickly pears around Cuyler Manor in Uitenhage.

  The insect that Europeans once guarded so jealously had become, in some places, a weapon against the plant it lives on.

  7578111214

• 8. Collapse and Comeback

  ›

  In the middle of the 19th century, artificial dyes such as alizarin crimson appeared, and demand for cochineal fell sharply. Spain took a serious financial blow, since a major industry nearly ceased to exist. Delicate hand breeding could not compete with modern methods or with falling production costs.

  The dye, nicknamed "tuna blood" after the Mexican name for the Opuntia fruit, went out of use. Through the 20th century, trade almost disappeared. For a time, people bred cochineal mostly to keep the tradition alive.

  Then worry about synthetic red dyes and food colorings, some suspected of being carcinogenic, pushed buyers back toward natural options. Natural does not guarantee safe. Still, studies show cochineal is neither carcinogenic nor toxic, though it carries a slight potential to trigger an allergy.

  By 2005, Peru was producing 200 tons of cochineal dye per year, and the Canary Islands 20 tons. Chile and Mexico also export it. France is believed to be the largest importer, with Japan and Italy also buying. Natural cochineal cost between US$50 and 80 per kilogram that year, while synthetic raw food dyes sold for as little as $10-20.

  The dye is unusually tough. It is one of the few water-soluble colorants that resists degradation over time, and it holds up against light, heat, and oxidation better than many synthetic food colors. Cochineal extract goes into beverages, and carmine into a huge range of products, including sausages, surimi, marinades, bakery toppings, jams, cheddar cheese, and sweets. It is also used in lipsticks, rouges, and blushes, and it is considered safe near the eyes. Pharmaceutical makers use it to color pills and ointments, and histologists use it to stain tissue.

  It also raises ethical questions at the table. Vegetarian and vegan consumers may reject it. Many Muslims consider carmine-containing food haram, because all insects except the locust are forbidden. Jews avoid the additive too, though it is not treif, and some authorities permit it because the insect is dried and powdered.

  A small number of people experience occupational asthma, food and cosmetic allergies, and in rare cases anaphylactic shock. In 2006, the FDA said it found no evidence of a significant hazard to the general population. In 2009, it ruled that food and cosmetic labels must name "cochineal extract" or "carmine". In the EU, the additive is E 120, while an artificial, non-allergenic cochineal dye is labeled E 124.

  Tradition survives too. Some towns in the Mexican state of Oaxaca still produce and use cochineal for handmade textiles, and in Guatemala, Heifer International has partnered with women who want to revive artisanal cochineal production.

  Replacing the insect has proved extremely difficult, because the molecule's structure is complicated. Chemists first synthesized carminic acid in the laboratory in 1991. In 2018, researchers engineered the fungus Aspergillus nidulans to make it. In 2021, they did the same with the bacterium Escherichia coli, a step toward a red made without a single insect.

  4851586963