“What is that White Cottony Stuff on my Prickly Pear Cactus?”

Cochineal on a prickly pear cactus.

Cochineal on a prickly pear cactus.

By Susan Campbell

We all love color in nature, especially this time of the year, but none are as vibrant as the color red.  “Since the beginning of history the color red has appealed to societies as a color meaning danger and courage, revolution and war, violence and sin, desire and passion.” (1)   No red dye was as vibrant in 1519 when Spanish conquistadors found the Aztecs selling an extraordinary red dye in the great market places of Mexico. They called it grana cochinilla or cochineal.   

“When Cortes invaded, he was amazed to find Montezuma and other nobles dressed in robes dyed a brilliant, vivid red. He was also amazed to see the native women’s hands and breasts painted the same intense color. In Tenochtitlan (now Mexico City) he found bags of dried cochineal sent as tribute to Montezuma, which were promptly shipped back to Spain. The dye was so much brighter than the rest and almost instantly in high demand in Europe. By 1600, cochineal was second only to silver as the most valuable import from Mexico.” (2)

Cochineal is a scale insect and is found on prickly pear cactus, Opuntia engelmanii.  As a rasping, sucking insect, it feeds on the tasty juices of the cactus. It produces a cottony white covering to protect itself from predators. Once plucked from the cactus, the insect is dried and dehydrated, then shipped to all parts of the world to be used in all sorts of ways. Dried cochineal is used in textile dying (such as wool),  cosmetics, food coloring, and artist’s paint. Today it is also used as a red dye in nutritional drinks. One of the most famous uses for cochineal was to dye the jackets of the British military “Redcoats” during the Revolutionary War.

Susan Campbell shows students the red dye of cochineal.

Susan Campbell shows students the red dye of cochineal.

In the City of San Antonio Natural Areas Education Classes, live cochineal are shown to students on the cactus, and dried cochineal is used to paint on rocks, paper, and wool fibers. To this day dried cochineal can still be purchased, but cochineal has been mostly replaced with longer lasting synthetic dyes.  

Ethnobotany is the scientific study of the relationships that exist between people and plants. Using cochineal to show how plants and insects were used by Native Americans, as well as early settlers in Texas, is a great way to teach this concept to student. They learn about the relationship and connection to nature and the history of this insect. The students also like seeing the name of cochineal extract (listed as carminic acid) in the ingredients section on their favorite red “bug juice” drink — Sobe Life Water.

For more information about the educational programs in the SA Natural Areas please check out these websites: www.sanaturalareas.org or www.philhardbergerpark.org   or http://www.sanantonio.gov/parksandrec/areas_gardens.aspx


  1. Greenfield, Amy Butler; A Perfect Red, Harper Perennial, 2005.

2. Behan, Jeff, The Bug That Changed History, http://www.gcrg.org/bqr/8-2/bug.htm