Family : Dactylopiidae
Text © Prof. Santi Longo
English translation by Mario Beltramini
The Carmine cochineal (Dactylops coccus) lives on the Cactaceae belonging to genera Opuntia and Nopalea © Giuseppe Mazza
The well-known Carmine cochineal, Dactylopius coccus O.G. Costa, 1829, is a homopteran True bug afferent to the Coccomorpha also better known as superfamily Coccoidea or Cochineals, from the Spanish “cochinilla”.
The females have an oval-shaped body with reduced antennae and legs.
Very developed are some pieces of the mouthpart having the shape of long stilettos able to pierce the food substrate for sucking the humours.
The adult males, if winged, are like tiny parasitic flies and as such have been mistaken in the past by observing the body equipped with two wings and the matings.
Their dimensions are more reduced if compared to those of the females that were thought to be small galls produced by the plants.
Taxonomically the species belongs to the genus Dactylopius, O.G. Costa 1829, the only one of the family Dactylopiidae, instituted by Signoret in 1875, including about ten species enfeoffed, almost exclusively, on Cactacee of the genera Opuntia and Nopalea.
Zoogeography
Like the other species of the genus Dactylopius, the Carmine cochineal is native to the neotropical region of America, in particular of Mexico, where it was grown to get a dye that, since pre-Columbian times, the natives produced and traded.
The Spanish conquistadores introduced the prized product in Europe, establishing a lucrative monopoly regime.
It was protected by very strict measures of control, intended to prevent the diffusion of the cochineal outside their colonies.
Later on, the British introduced about fifty species of Cactaceae in South Africa, in Australia and in the Asian colonies in order to activate the breeding of the Carmine cochineal and to obtain the prized dye.
In Europe it rapidly replaced those of lesser quality that were obtained from other cochineals living mainly at the expense of the oaks, whose most important species was the Kermes, Kermococcus vermilio (Planchon, 1864), known also as Cochineal of the scarlet or Kermes of the oaks that lives at the expenses of Quercus coccifera, Quercus ilex and Quercus suber.
The first age young forms have a red body due to the presence in their blood, called hemolymph, of carminic acid © Jose Mª Perez Basanta
Ecology-Habitat
Nowadays, the Carmine cochineal is to be considered as cosmopolitan in the tropical zones were grow the opuntias and the temperatures stand between 24 and 28 °C and the relative humidity is not high, the rains are scarce and do not coincide with the occurrence of thermal drops. Such conditions, in Europe, realize only in the Canary Islands.
In the Mediterranean Basin Dactylopius coccus has acclimatized in some zones of Algeria, of France, of Morocco, of Spain and of Turkey.
Neanids and adult females covered by wax. These tend to merge in dense colonies to amplify the attractive efficacy of their sexual feromones that make males discover even the little exposed sites © Giuseppe Mazza
Its introduction in Sicily and in Sardinia has been tried several times, unfortunately, without success.
An experiment, sustained by the European Community, has been carried out in Sicily by the end of the last century, breeding the Cochineal in a protected environment in order to obtain the natural dye.
Morphophysiology
The adult females have an about 5 mm long and about 3 mm broad body.
On the whole their globular shape and the coating of tiny granules of white wax reminds that of a small chickpea.
The waxy filaments, secreted by the juvenile stages mixed with the sugary excrements render the colonies sticky to the touch.
The females tend to merge in dense colonies in order to amplify the attraction efficacy of the volatile substances (sexual pheromones) that attract small males in the less exposed sites of the plant where they do live.
In the microscopic preparations, necessary for discriminating the species from the others of the same genus, highlight the antennae, about 0,3 mm, formed by 7 articles (antennomeres), and the legs, about 0,9 mm long.
In the dorsal part of the body are present bristles whose number and dimensions are inferior to those of the other species of the same genus; the anal opening is reduced to a small crack, not surrounded by bristles.
Ventrally, in the fore part of the body, are inserted the antennae, the stinging and sucking mouthpart, the legs and the genital opening.
The first juvenile stage (denominated first age neanid or N1) has the body of oval shape, about 1,3 mm long, with antennae formed by 6 articles and long legs. On the body are present long waxy threads secreted by the ceriparous glands, useful for the dispersion of the N1, done by the wind. The following juvenile stages secrete few waxy threads.
The females able to reproduce are called neotenic as their appearance is like that of the juvenile stages.
Adult male, like a gnat, just fluttered among the cocoons where the metamorphosis of the male line takes place © Walter P. Pfliegler
The males have a development defined neometabolic because the last juvenile stage effects one metamorphosis inside a silky white conical involucre.
The adult males have an about 1,5 mm long body of reddish colour covered by minute granules of wax, the head and the thorax are darker than the abdomen.
The antennae are 0,7 mm long and are equipped with numerous sensory hairs. In the second segment of the thorax are present two wings. The extremity of the abdomen is elongated and presents two waxy filaments longer than the whole body.
The male has long antennae with several sensilla to locate and reach, flying, the sedentary females © Vuk Vojisavljevic
Ethology-Reproductive Biology
The Carmine cochineal settles mainly on the 1-2 years old cladodes of the prickly pears, at whose expense it completes the development in about 3 months.
From the egg, that hatches already inside the maternal body, shells the first mobile stage (Neanid 1), followed by a second (Neanid 2) and, after the second moult, the one of female that, after mating, reproduces.
In the males the two stages of neanid are followed by two other nymphal ones called prepupa and pupa, and, after the metamorphosis, the adult one.
The species does not interrupt the development during the year, and consequently the number of generations varies depending on the trend of the temperatures and of the relative humidity, as well as on the microclimate of the site where it lives.
It is not by chance that the little mobile females are installed preferably in the most sheltered zones of the plant.
Numerous species of natural foes live at expense of the various stages of the Cochineal.
In South America, active predators are the larvae of a Syrphid Dipteran of the genus Allograpta.
In the Canary Islands, the adults and the larvae of the Coccinellid Coleopteran Exochomus flavipes predate the juvenile stages.
All species of Dactylopius owe their colouring to the presence in the body of carminic acid.
What is possible to get from the exsiccated females of Dactylopius coccus is in greater quantity than that of the other species.
Such “biologic” colouring is used as indicator and reagent in histology and in bacteriology.
Before the advent of the cheapest synthetic dyes, aniline based, the aqueous solution of the extract of the exsiccated bodies of the Cochineal was widely employed in the pharmaceutical, cosmetic and alimentary industries as well as in that of the dyes.
The shades of colour going from the fuchsia to the red and the violet are obtained by adjusting the pH with modifiers of dye and mordants.
Factory with cladodes of prickly pear artificially infested for the breeding the females just collected as raw material before the dye © Karen Elwell
For obtaining great quantities of such raw material the Aztecs developed adequate breeding systems of the Cochineal, that are partly adopted still now in South Africa, in India, as well as in Central and South America, where the breeders, before the rainy period, collect the pre-ovigerous females present on most plants and shelter some cladodes that they will utilize for infesting the plants during the dry period, more favourable to the development of the Cochineal and reactivate the breeding.
A more recent system of breeding foresees the sampling in the field of the cladodes of the Opuntia-ficus indica and their transfer to a protected environment where, with appropriate hooks hung from suitable supports, the inoculation of the cochineal is done putting in close contact with each cladode a container of vegetable fibers containing the ovigerous females.
Dried adult females, ready to be reduced in powder for their employment in the industry for numerous utilizations © Santi Longo
The young forms just produced reach the cladode on which they fix and in about three or four months they become adult females ready to be picked up and dried in the sun or in special ovens.
Then the powdery wax is eliminated and the dried bodies, of dark grey colour, are reduced to powder.
To obtain one kilo of dye is necessary to reduce the powder from 80 to 100 thousand adult females that have not yet matured the eggs.
From the powder obtained in such a way, after a treatment with water is extracted the carminic acid contained in it.
Laboratory with hanging high cladodes, loom and the material for hand crafting with wools of various shades of colour obtained varying the bath pH © Karen Elwell
The dye thus obtained is treated with aluminum salts to render the lacquer more brilliant.
The addition of ethanol is necessary to precipitate the compound and obtain a water-soluble powder.
In the past the main employment of the obtained colour occurred in dye factories where it is possible to get fabrics and wools with different shades of fuchsia, red and violet colour by regulating the pH of the bath with the modifiers of dye and mordants.
Presently it is employed in cosmetics for colouring lipsticks and blushers, as well as in the food industry, with the code E120, to give colour to yoghurts and to red fruit juices.
Interesting mural by Arturo Bastia Bustos in Oaxaca Palacio Museum. It shows the various phases of the productive process from the harvest in the field of the cochineal done by the women, up to the colouring of the fabrics with Dactylopius coccus that was done in Mexico already in pre-Columbian eras © Karen Elwell
Synonyms
Dactylopius coccus Costa, 1829, Coccus cacti Mooder, 1778; Coccus cactus Signoret, 1875; Coccus cacti domestica Meunier, 1884; Dactylopius mexicanus (Meunier,1884) Dactylopius sativus (Signoret, 1875).
The common names with which this cochineal has been indicated refer to the dried specimens for getting the dye.
Besides Caemine cochineal, it has been indicated as: Cocciniglia grana Cocker, 1897; Cocciniglia, Miller 1925; Grana fina Essig, 1928; Dattilopio cocco, Grana fina del Messico, delle Canarie Silvestri, 1939; Grana cultivada McKenz, 1956; Cochinilla fina AnantaSuMu, 1957; Cochinilla cultivada, Borchs 1966.
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