By Julie Etra—
Cochineal, Dactylopius coccus, is a scale insect that resides and feeds parasitically on the pads of nopal , known as prickly pear cactus, which when processed produces a bright red color that was unknown to the conquering Spaniards. The insect produces carminic acid, the source of the pigment, which deters other predators and thus protects the insect. Only the female produces the color when she is crushed, sometimes along with eggs, either fresh or dried. Carminic acid can be mixed with aluminium or calcium salts to make carmine dye. It takes about 70,000 dried cochineal and around 25,000 fresh insects to produce 0.45 kg (one pound) of dye. Historically in Mexico it was primarily produced in the state of Oaxaca by the Zapotecs and Mixes at least three centuries before the arrival of the Spaniards. It was also cultivated to a lesser extent by the Aztec (Tenochtitlan) and Otomi (Hidalgo, México, Querétaro, Guanajuato, Puebla, Tlaxcala, Michoacán and Veracruz) cultures. The plant was bred to eliminate the spines on the cactus pads and was thus easier to cultivate for cochineal production. In addition to textiles, it was used for painting manuscripts as early as the thirteenth century.
Traditional (and non-traditional) production is a tedious labor-intensive process. Historically, the insects were sun dried, steamed or boiled, all which produced slightly different colors, prior to being ground into a fine powder.
Farming of cochineal takes place on a nopal farm, either by planting infected pads (which readily root, and thus are easy to propagate vegetatively, as is true of all species of Opuntia) and by infecting existing plants with hand placement of the insects. An alternative method consists of placement of small baskets, called Zapotec nests, on the pads. The baskets contain fertile females which then migrate from the baskets and infest the host plant. Both methods require protection from the elements for the entire three-month maturation cycle, at which time the new cochineals are allowed to reproduce and/or are collected by knocking or brushing the insects into an awaiting bag, after which they are usually sun or oven dried to obtain about 30% of their original weight, necessary for stable storage. Pest control is required throughout the entire cultivation process to ensure success of this coveted product. The dried, crushed insects are then sold to small local processors or exported.
Today’s producers may add aluminum salts are added as a precipitate to the carminic acid. By manipulating the pH and adding mordants, such as acidic lime, or metals salts, the color can be shifted to various shades. Lime juice produces purple while vinegar, also an acidic mordant, can shift the color to a brighter orange-red.
This pre-Hispanic, Oaxacan dye was an eye-opening surprise for the conquering Spaniards who quickly understood its value in European markets as no other comparable color existed in Europe at the time. It rapidly became the most lucrative Spanish colonial trade item following silver, especially coveted as a status symbol by the wealthy, which included the clergy. The monopoly was strictly controlled by the Spanish government until the 19th century when synthetic dyes became available.
The construction of the Church of Santo Domingo in Oaxaca City, originally a monastery and now a museum and ethnobotanical garden, was entirely funded by the sale of this dye. The museum houses an excellent exhibit on the bug and its rise to become an invaluable trade item. The gardens behind the museum are home to Opuntia ficus -indica, amongst dozens of other native species, so one can observe the scale insect on the host plant.
Peru is now the leading producer of cochineal with over 80% of the world’s supply followed by Mexico and the Canary Islands, all three industries being established by the conquering Spaniards. Chile and Argentina are also significant contributors to the current market.
These days it is a common food dye, listed as carmine or carminic acid or even cochineal extract. It is found in yogurt and countless other products including cosmetics.
As an interesting aside, the red uniforms worn by the British forces in the US Revolutionary War were primarily dyed with the roots of madder, although some wealthier officers preferred the brighter, more expensive red derived from cochineal. Of course they had the means to purchase the uniforms.
If you want to see the insect and how it is used plan a visit to Teotilán del Valle, a famous community of weavers and their gorgeous tapetes (wall hangings) south and east of Oaxaca City.