Cochineal

Cochineal

Cochineal (Coccus cacti L.), insect of the familie of scale insect (Coccidae). The carmine male is 1.6 mm long, with two shaded light brown wings, ten-membered antennae and two long caudal bristles. The female is 2 mm long, almost spherical, frosted white, wingless. Cochineal lives in Mexico on a cactus, Nopalea (Opuntia) coccinellifera (Nopal, see panel »Cacti«, Fig. 21), and is cultivated there as in Central and South America, in West and East India, at the Cape, as well as in Spain, Algeria, Java and on the Canary Islands on said plant and on other spineless species of the same genus.

Females attach themselves to the mother plant, swell significantly and lay their eggs in the white secretion which completely covers sections of the plant. The nymphs that hatch after eight days look similar to the mother, except that the secretion from their wax glands covers them in a stringy cloak. They molt repeatedly and are fully grown in two weeks. The male larvae live in cylinders of wax threads, open at the rear, which are joined by an adhesive. The males die after mating, whereas the females continue to lay eggs for 14 days. There are several reproductive cycles during the summer.

Harvested insects are killed by steam and dried on trays. They form semicircular, wrinkled bodies the size of a split pea, are black-brown, more or less frosted white, dark purple on the inside, taste bitter, somewhat astringent and stain the saliva red. The first harvest of the year yields a more valuable product (zaccadilla) than the following ones. Of all the varieties, the Honduran is the best, followed by Tenerife, Veracruz, Java and Spanish cochineal. Cochineal harvested from wild Opuntia (possibly a different species) is called wild cochineal. The pigment in cochineal is carminic acid. Cochineal is used to produce carmine, carmine lake, ammoniacal cochineal (by leaching with ammonia and precipitating with hydrated alumina); with the introduction of coal tar dyes, however, it has lost significant market share.

Cochineal was also used medicinally in the past. It was cultivated in pre-Columbian Mexico. Francisco López de Gómara provided the first description of the cochineal in 1525; but the drug was still considered to be of vegetable origin until the dispute was settled by the research of Dutchman Ruyscher in 1725. About 300 kg of cochineal are harvested from 1 hectare of nopal plantation, and there are about 140,000 animals per 1 kg.

In earlier times, a red scale insect Porphyrophora polonica L. (Polish cochineal, Saint John’s blood), which lives on roots of several plants, especially Scleranthus perennis, in Northeastern Germany, Poland, Russian, Sweden, Hungary, was harvested around Saint John’s, particularly in Poland. The insect was a trade item of some importance, but has long since been supplanted by the much more abundant cochineal. False cochineal, see Kermes.

Source: Meyers Großes Konversations-Lexikon, 6. Auflage 1905–1909

Carmine