"So, naturalists observe, a flea has smaller fleas that on him prey; and these have smaller still to bite ’em; and so proceed ad infinitum."
- Jonathan Swift

February 15, 2010

February 15 - Dactylopius coccus

Fashion week + President’s Day = cochineal!

Dactylopius coccus, commonly known as cochineal, is a scale insect (a sternorrhynchan, like the aphids), which is widely used in the fashion industry. These insects produce carminic acid, which, when combined with aluminum or calcium salts, is used to make carmine dye. D. coccus is native to Mexico and South America, where the females are parasites on cactus plants in the genus Opuntia. Only the male D. coccus insects have wings. The juvenile stages of D. coccus, the nymphs, disperse using long wax filaments that allow them to parachute in the wind (much like many spiders do with silk). Ever since the time of the Aztecs and Mayans, people have been harvesting these insects for their red pigment. The scale insects are collected from the cacti, boiled in water and allowed to dry thoroughly. For pure carmine, a more involved chemical process is used, whereby the pulverized insects are boiled in ammonia and then the red salts are precipitated with alum. In colonial times, Europeans began to use carmine dye as well, particularly to make fabrics, including those of the British “Redcoats”. Although synthetic red dyes were used for a time being, their link to cancer and expense to make has led to a resurgence in “natural red coloring” – in other words, for carmine dyes derived from D. coccus. It is widely used in the U.S. as a food coloring, but is also used as a fabric dye and as a pigment to make cosmetics such as lipsticks and blushes. Check the ingredients label the next time you eat something red or use make-up – chances are, you’re enjoying a dye derived from a parasitic insect.


  1. First time I hear about a parasitic phytophagous insect. Parasitic plants feed on other plants, but parasitic animals (parasite or parasitoid) feed on other animals. It's a naive question, but what difference do you do between parasitic insect on plants and herbivorous insect?

  2. Yes, it is a slippery slope, isn't it? I'm trying to stick to the notion that if an organism lives in or on another and derives its nutrition from this source, it's a parasite. So, in this sense, the scale insect is analogous to a tick that would be living on a mammal and feeding on its blood. I see this as somewhat different from an herbivorous insect that chews on a leaf (though some do, of course spend most of their life on this plant). Perhaps it's a matter of scale - the herbivorous beetle can't snatch up a whole plant like a carnivore would do -it's forced to take tiny little bites.

  3. If anyone is interested in the history of cochineal, I recommend A Perfect Red by Amy Butler Greenfield. Subtitle: Empire, Espionage, and the Quest
    for the Color of Desire. Intriguing and well-written!

  4. The definition I have in my mind is that a parasite is an organism that obligately associates with another organism as a requirement to complete its life-cycle. So for example, a cuckoo is a (brood) parasite and cannot complete its life-cycle without its host (in fact many aspects of the coevolutionary relationship between cuckoo and its host mirrors that of more "conventional" host-parasite coevolution).

    I think the French eco-evolutionary parasitologist put it best when he called parasitism and other forms of symbiosis "durable interactions".

  5. I never thought about it, but as I think about it... It would seem humans are the biggest parasite. We suck the blood out of each other to live. We suck the sap from trees. We suck the milk from cows. We steal the eggs from chickens. The list goes on and if any other animal did any of these things, they would be labled a parasite. Wouldn't they?