Opuntia cactus covered with scale insects

Opuntia cactus covered with white scale insects.

I hate scale. This persistent insect pest eventually caused the untimely death of my prized Meyer lemon tree. During the annual winter infestations, I would try to keep the insect in check with periodic applications of Neem oil, but after several years of battle, I grew weary of fighting and let the tree die.

Scale isn’t all bad, though. On a recent trip to Mexico I discovered that there’s a type of scale (different from the one that plagued my lemon tree) that people have been putting to good use for thousands of years. Cochineal (Dactylopius coccus) latches onto several species of opuntia cactus, most notably Opuntia ficus-indica. The Zapotec people in Oaxaca, Mexico, collect the insects from the cactus pads growing in the region. The pests are dried, ground and mixed with liquid to create a vibrant dye that ranges in color from red to purple. This dye can be used in many things, including foods and fabrics.

The red color in this rug is made with wool that’s been dyed with cochineal.

Samuel Bautista Lazo and his family are Zapotec weavers that use cochineal to tint the wool they spin and weave into rugs. The weavers can produce lighter red tones by adding acid (lemon juice), and more purple tones by adding crushed limestone. In fact, all of this family’s wool is tinted with natural sources: mostly from plants and, of course, from cochineal, the scale insect.

“We use natural dyes because our ancestors taught us how to use them; it was how they painted their manuscripts and murals,” Bautista says. “Plus, it is well-known now that synthetic dyes can be highly toxic—another reason we use natural dyes.”

Celestino Bautista Lazo

Celestino Bautista Lazo works on a new rug, featuring yarn dyed with cochineal and plant parts.

Among the plants foraged for dyes:
Walnut leaves and shells provide brown tones


granate peel is used to make orange to yellow hues

Marigold flowers (cempazuchitl) can be used to create golds and yellows

Indigo, a shrub, yields beautiful, blue tones

-David Grist, Online Content Coordinator

Wool yarn being dyed with cochineal. The yarn simmers for several hours to set the color.