This is a food colouring derived from female cochineal beetles. It gives a pink, purple or red colour.
The insects are about 1/4 of an inch (6 mm) long.
Technically, they are "scale insects." The bug attaches itself to cactuses, and feeds on it. While doing so, it exudes a white waxy liquid that forms a shell around it, to protect it. The females are wingless, and have six legs.
The insects are harvested from within their wax shells, then dried and ground up, then heated, and filtered.
Aztecs used the bug to dye cloth. The Spanish learnt from them, and introduced the insect to Europe, because the red colour was more vivid than other dyes could produce.
It is used in Campari, and Alchermes, and in colouring artificial crab meat, as well as in candies, juices, frozen treats, etc.
The dye has also been used in making redcoats for the British army and Canadian Mounties, as well as clothing for Catholic cardinals.
In the late 1800s, artificial dyes overtook the use of cochineal. In the 1990s, it regained popularity after concern about synthetic food additives.
70,000 of the bugs are needed to make one pound (450g) of cochineal powder.
Cochineal Extract is reputed to cause allergic reactions in some people, though government health agencies aren't convinced yet.
Nevertheless, people who are on vegetarian or Kosher diets need to particularly watch for the presence of such colourings derived from bugs.
Growing Cochineal was an important part of the economy of the Canary Islands from about 1825 to the 1870s, at which time the business was hurt by the introduction of new, artificial colourings.
The Spanish name, "alquermes", comes from the Arabic word, "Quirmiz", which means "scarlet".
Its "E" number is E120.