A prickley pear with cochineal insect

What’s bugging the prickly pears?

Currently some of the prickly pear cacti around New Mexico are sporting white spitball-like wads among the spines. They hold a story that begins before the 1500s, a story involving why red is the color of royalty, how cactus got to the Old World, and the Aztecs’ contribution to red vitamin pills.

Historically, red has been one of the colors most prized by crown, church and nobility. Kings are often depicted in red robes. When we wish to treat someone special, we roll out the red carpet. The reason for this color association is an economic one: prior to the 1500s, the only source of colorfast red dye was a tiny scale insect that grew on oak trees in Europe. Dye makers had to gather 70,000 of the tiny creatures to produce one ounce of dye. Only royalty could afford it: Caesar has a full red robe, but his lieutenants only had red stripes on their robes.

All of this changed with the invasion of Mexico by Cortez in the early 1500s. When Cortez entered the Valley of Mexico, he was most impressed by the level of civilization and by the riches he beheld. He noticed that even the peasants wore red. As the Aztec women washed the garments in the streams, the color seemed fast. Through the writings of Cortez’ scribe, we can almost see dollar signs forming in his eyes.

Cortez found out from the Aztecs that the source of this brilliant color was small “grains” that occurred in fuzzy white spots on the prickly pear cactus. When these “grains” were squashed, they yielded a deep magenta “juice.” Untreated, this color is not stable in water, but the Indians gathered the “grains,” fried them on a comal (griddle), added lime juice, metal ores and other chemicals and produced a permanent dye called cochineal.
The Aztecs related a legend about two gods who fought bitterly for the possession of a field of prickly pear. Their blood splattered on the cactus, giving it the power to pass on to posterity the “blood of the gods”.

The Spanish began shipping bags of the dye back to Spain. With cheap Indian labor, the profits were enormous. “Grana cochinilla” was, after precious metals, the most important Mexican export for hundreds of years. A reason for the huge profit was that a small guild of dye makers kept the origin of cochineal a secret for over 300 years. That any secret can be kept for three centuries is amazing. This one is especially so when one considers the money at stake and the fact that prickly pear cactus was shipped to Spain early on so that the industry could proceed there.

Until about 1725, it was believed that cochineal was the seed of a plant, even though Dr. Martin Lister in 1672 conjectured that it was some sort of insect, and in 1703 Antony van Leeuwenhoek confirmed its true insect nature by aid of the microscope. Yet, the news was slow to disseminate. When explorers from competing European nations came to Mexico to find the secret of cochineal, they were looking for seeds instead of insects. Finally, in the 1800s, a spy infiltrated the dye factory, found that it was bugged, and cochineal became widely available at reasonable prices.

Prickly pear cactus was brought to Africa and Spain and now looks so at home that a tourist might assume it was native to the Old World. Australia also imported cactus for this valuable dye with disastrous consequences. By 1925, 60 million acres of valuable rangeland were covered by prickly pear.

Until the early 1900s, cochineal was the main red dye in military uniforms and clothing, in foodstuffs and in many cosmetics. Michelangelo painted with it, the British “redcoats” and Canadian Mounties’ uniforms were dyed with it. Betsy Ross used it for our first flag. The Navajo, who had no red in their original weavings, traded in the 1800s for cochineal-dyed flannel blankets (bayetas) of Spanish soldiers, unraveled them and reused the threads. Then aniline dyes (from coal tar) and other synthetic dyes were invented and no one wanted to bother with bugs anymore (except weavers who always treasure the color). However, when red dye #2 was removed from the market as a possible carcinogen, there arose a need for a harmless “organic” red coloring. So cochineal has made a comeback in cosmetics, fruit juices (ruby red grapefruit juice), jams and jellies, certain red soda pops, some alcoholic drinks (Campari), red vitamin coatings, red gelatin desserts, red candies, and chewing gum. On the list of ingredients, euphemism such as E120 or the word “carmine” disguises its buggy origin. The FDA permits cochineal extract and carmine as safe color additives for food and cosmetics. Despite the “ewwwww” factor, when one considers the unhealthy alternatives, better this red than dead.

The insects themselves are fascinating. They are related to aphids, mealy bugs and scale insects. The tiny winged males live only long enough to impregnate the females, who are little more than bags of eggs with a feeding proboscis stuck into the cactus. What one observes on the cactus (under the white fluff) are the females, footless and pregnant. They secrete the white, web-like, wax-base “cocoon” for camouflage and to prevent desiccation. They also produce a bitter, astringent chemical called carminic acid that is very effective in repelling potential predators such as ants. However, since there is no winning the evolutionary arms race, it is not surprising that one predator has gotten past the defense. A caterpillar of one moth species eats cochineal insects and stores the bitter chemical in its gut to be used later against the ants that are its natural enemies.

Reprinted with permission from Share with Wildlife (Summer, 2005), a publication dedicated to the conservation of all New Mexico wildlife.