In the deserts of the Americas you might notice that the prickly pear cactus plants (genus Opuntia) sometimes are covered with what looks like white spit-wads. If you look closely, or touch one of the deposits, it's silky white web-like material. This is actually a protective covering of a little insect called a cochineal (Dactylopius sp.), which is a parasitic scale insect. The insect itself is tiny, about 3-4 mm across; their bodies contain carminic acid, which is a vivid purple-red color - presumably nasty-tasting to discourage predation. If you even gently bump one of them, they ooze this red liquid, which instantly will dye your finger.
I had read that cochineal was one of the earliest and most valuable sources of red dye. Aztecs and Mayas cultivated them; and during the time of the Conquistadores, cochineal dye powder was the second most important economic export after silver - that is a lot of insects!
Because of my interest in natural dyes and inks (see labels for those subjects), I have been looking for a colony of cochineal so I could experiment with using their pigment for coloring in my journal. Earlier in August, visiting my parents in southwestern New Mexico, I was delighted to find some infestations by this sessile parasite. I collected about 20 of them in a margarine tub:You can see the bright magenta color. I did some research, because I had initially read that the color they produced was red-red, as in the British redcoats, and in Betsy Ross' flag. The original dye preparation involved adding an acid, so I added a little vinegar to a bit of cochineal liquid, and voila, it turned a rich red.
Right now my insect bodies are drying, and I will grind them and add an acid - either vinegar or lemon juice - and see how it goes with use as a pigment in my journaling.