in zoology, a genus of insects belonging to the order of hemiptera. The rostrum proceeds from the breast; the belly is briefly behind; the wings of the male are erect; and the female has no wings. The species are 22, denominated principally from the plants they frequent. The most remarkable species are:

1. The coccus hesperidum, or green-house bug, which is oval, oblong, of a brown colour, covered with a kind of varnish: it has six legs; with a notch and four brittles at the tail. It infests orange trees and other similar plants in green-houses. When young, it runs upon the trees; but afterwards fixes on some leaf, where it hatches an infinity of eggs, and dies. The male is a very small fly.

2. The coccus phalaridis. The male of this species is small. Its antennae are long for its size. The feet and body are of a reddish colour, nearly pink, and sprinkled with a little white powder. Its two wings, and the four threads of its tail, are snow white, and of those threads two are longer than the rest. It is to be found upon the species of gramin which Linnaeus calls phalaris. The female contrives, along the stalks of that dog-grass, little nests, of a white cottony substance, in which she deposits her eggs. The small threads of her tail are scarcely perceptible.

3. The coccus cacali, a native of the warmer parts of America, is the famous cochineal animal, so highly valued in every part of the world for the incomparable beauty of its red colour, which it readily communicates to wool and silk, but with much more difficulty to linen and cotton. This insect, like all others, is of two sexes, but exceedingly dissimilar in their appearance. The female, which alone is valuable for its colour, is ill-shaped, tardy, and stupid: its eyes, mouth, and antennae, are fixed too deep, and are so concealed in the folds of the skin, that it is impossible to distinguish them without a microscope. The male is very scarce, and is sufficient for 300 females or more; it is active, small, and slender, in comparison with the female; its neck is narrower than the head, and still narrower than the rest of the body. Its thorax is of an elliptic form, a little longer than the neck and head put together, and flattened below; its antennae are jointed, and out of each joint issue long flender hairs that are disposed in pairs on each side. It has six feet, each formed of distinct parts. From the posterior extremity of its body two large hairs or brittle are extended, which are four or five times the length of the insect. It bears two wings that are fixed to the upper part of the thorax, which falls like the wings of common flies when it walks or rests. These wings, which are of an oblong form, are suddenly diminished in breadth where they are connected to the body. They are strengthened by two oblong muscles, one of which extends itself on the outside all round the wings; and the other, which is internal and parallel to the former, seems interrupted towards the summit of the wings. The male is of a bright red; the female of a deeper colour. They are bred on a plant known in Oaxaca in New Spain, and all those parts where it abounds, by the name of nopal, or nopalcea, the Indian fig-tree. See Cactus.

The cochineal was formerly imagined to be a fruit or seed of some particular plant; an error which probably arose from an ignorance of the manner in which it is propagated; but at present every one is convinced of its being an insect, agreeably to its name, signifying a wood-louse, which generally breeds in damp places, especially in gardens. These insects, by rolling themselves up, form a little ball something less than a pea: and in some places are known by the name of baquitas de San Antonio, i.e. St Anthony's little little cows; and such is the figure of the cochineal, except that it has not the faculty of rolling itself up; and its magnitude, when at its full growth, does not exceed that of a tick common in dogs and other animals.

The juice of the plant on which these insects breed, is their sole nourishment, and becomes converted into their substance; when, instead of being thin and watery, and to all outward appearance of little or no use, it is rendered of a most beautiful crimson colour. The plant is in May or June in its most vigorous state, and at this most favourable season the eggs are deposited among the leaves. In the short space of two months, from an animalcule, the insect grows up to the size above mentioned; but its infant state is exposed to a variety of dangers; the violent blasts of the north wind sweep away the eggs from the foliage of the plant; and, what is equally fatal to their tender constitutions, flowers, fogs, and frosts, often attack them, and destroy the leaves, leaving the careful cultivator this only resource, namely, that of making fires at certain distances, and filling the air with smoke, which frequently preserves them from the fatal effects of the inclemency of the weather.

The breeding of cochineal is also greatly obstructed by birds of different kinds, which are very fond of these insects; and the same danger is to be apprehended from the worms, &c., which are found among the plantations of nopalos; so that unless constant care be taken to fright the birds away from the plantation, and to clear the ground of those various kinds of vermin which multiply so fast in it, the owner will be greatly disappointed in his expectations.

When the insects are at their full growth, they are gathered and put into pots of earthen ware; but much attention is requisite to prevent them from getting out, as in that case great numbers of them would be lost; though there is no danger of it, where they are at liberty on the nopal leaves, those being their natural habitation, and where they enjoy a plenty of delicious food; for though they often move from one leaf to another, they never quit the plant; nor is it uncommon to see the leaves entirely covered with them, especially when they are arrived at maturity. When they have been confined some time in these pots, they are killed and put in bags. The Indians have three different methods of killing these insects; one by hot water, another by fire, and a third by the rays of the sun; and to these are owing the several gradations of the colour, which in some is dark, and in others bright; but all require a certain degree of heat. Those therefore who use hot water are very careful to give it the requisite heat, and that the quantity of water be proportioned to the number of insects. The method of killing the creatures by fire is to put them on shovels into an oven moderately heated for that intention; the fine quality of the cochineal depending on its not being over dried at the time of killing the insects; and it must be owned, that among the several ways made use of to destroy this valuable creature, that of the rays of the sun seems to bid fairest for performing it in the most perfect manner.

Besides the precaution requisite in killing the cochineal, in order to preserve its quality, it is equally necessary to know when it is in a proper state for being removed from the leaves of the nopal; but as experience only can teach the cultivator this necessary criterion, no fixed rule can be laid down. Accordingly, in those provinces where the cultivation of these insects is chiefly carried on, those gathered by Indians of one village differ from those gathered in another; and even those gathered by one person in the same village, are often different from those gathered by another; every individual adhering to his own method.

The cochineal-insect may, in some circumstances, be compared to the silk-worm, particularly in the manner of depositing its eggs. The insects destined for this purpose are taken at a proper time of their growth, and put into a box well closed, and lined with a coarse cloth that none of them be lost; and in this confinement they lay their eggs and die. The box is kept close shut till the time of placing the eggs on the nopal, when, if any motion is perceived, it is a sufficient indication that the animalcule has life, though the egg is so minute as hardly to be perceived; and this is the seed placed on the foliage of the nopal, and the quantity contained in the shell of a hen's egg is sufficient for covering a whole plant. It is remarkable that this insect does not, or at least in any visible manner, injure the plant, but extracts its nourishment from the most succulent juice, which it sucks by means of its proboscis through the fine teguments of the leaves.

The principal countries where the cochineal insects are bred, are Oaxaca, Tlascala, Chulula, Nueva Galicia, and Chiapa, in the kingdom of New Spain; and Hambato, Loja, and Tucuman in Peru; but it is only in Oaxaca that they are gathered in large quantities, and form a branch of commerce, the cultivation of these little creatures being there the chief employment of the Indians.

Though the cochineal belongs to the animal kingdom, of all others the most liable to corruption, yet it never spoils. Without any other care than merely that of keeping in a box, it has been preserved for ages. In drying, it loses about two-thirds of its weight. When dried, it is sorted into large entire grains, and small or broken ones; the first are called by the Spaniards grana, the latter granilla. In trade, four sorts are distinguished, Moisque, Campoflanes, Tetrafalcate, and fijocaster; of which, the first is accounted the best, and the last the worst. The three first are named from the places where they are produced; the latter from its being found wild without any culture.

In medicine, cochineal has been strongly recommended as a sudorific, cardiac, and alexipharmaic; but practitioners have never observed any considerable effects from it. Its principal consumption is among dyers. See the article Dyeing.

4. The coccus ilicis, or that forming the kermes grains, inhabits the quercus coccifera of the southern parts of Europe. Mr Hellot of the French Academy of Sciences, in his Art of Dyeing, chap. 12, says it is found in the woods of Vauvert, Vendemen, and Narbonne; but more abundantly in Spain, towards Alicante and Valencia. It not only abounds in Valencia, but also in Murcia, Jaen, Cordova, Seville, Extremadura, la Mancha, Serranias de Cuenca, and other places. In Xixona and Tierra de Rellue, there is a district called De la Grana, where the people of Valencia first began to gather it, whose example was followed all over Spain. It has some years produced 30,000 dollars (5000 l.) to the inhabitants of Xixona.

Both ancients and moderns seem to have had very confused notions concerning the origin and nature of the kermes; some considering it as a fruit, without a just knowledge of the tree which produced it; others taking it for an excrement formed by the puncture of a particular fly, the same as the common gall observed upon oaks. Tournefort was of this number. Count Marigliani, and Dr Nifole a physician of Montpelier, made experiments and observations, with a view of further discoveries; but did not perfectly succeed. Two other physicians at Aix in Provence, Dr Emeric and Dr Garidel, applied themselves about the same time, and with greater success; having finally discovered that the kermes is in reality nothing else but the body of an insect transformed into a grain, berry, or hulk, according to the course of nature.

The progress of this transformation must be considered at three different seasons. In the first stage, at the beginning of March, an animalcule, no larger than a grain of millet, scarce able to crawl, is perceived sticking to the branches of the tree, where it fixes itself, and soon becomes immoveable; at this period it grows the most, appears to swell and thrive with the sustenance it draws in by degrees. This state of rest seems to have deceived the curious observer, it then resembling an excrescence of the bark; during this period of its growth, it appears to be covered with a down, extending over its whole frame like a net, and adhering to the bark; its figure is convex, not unlike a small floe; in such parts as are not quite hidden by this soft garment, many bright specks are perceived of a gold colour, as well as stripes running across the body from one place to another. At the second stage, in April, its growth is completed; its shape is then round, and about the size of a pea; it has then acquired more strength, and its down is changed into dust, and seems to be nothing but a hulk or a capsule, full of a reddish juice not unlike discoloured blood. Its third stage is towards the end of May, a little sooner or later according to the warmth of the climate. The hulk appears replete with small eggs, less than the seed of a poppy. These are properly ranged under the belly of the insect, progressively placed in the nest of down that covers its body, which it withdraws in proportion to the number of eggs: after this work is performed, it soon dies, though it still adhere to its position, rendering a further service to its progeny, and shielding them from the inclemency of the weather, or the hostile attacks of an enemy. In a good season they multiply exceedingly, having from 1800 to 2000 eggs, which produce the same number of animalcules. When observed with the microscope in July or August, we find, that what appeared as dust, are so many eggs or open capsules, as white as snow, out of each of which issues a gold-coloured animalcule, of the shape of a cockroach, with two horns, six feet, and a forked tail. In Languedoc and Provence the poor are employed to gather the kermes, the women letting their nails grow for that purpose, in order to pick them off with greater facility.

The custom of lopping off the boughs is very injurious, as by this means they destroy the next year's harvest. Some women will gather two or three pounds a day; the great point being to know the places where they are most likely to be found in any quantity, and to gather them early with the morning-dew, as the leaves are more pliable and tender at that time than after they have been dried and parched by the rays of the sun; strong dews will occasionally make them fall from the trees sooner than usual; when the proper season passes, they fall off of themselves, and become food for birds, particularly doves. Sometimes there will be a second production, which is commonly of a less size with a fainter tinge. The first is generally found adhering to the bark, as well as on the branches and stalks; the second is principally on the leaves, as the worms choose that part where the nutritious juice preserves itself the longest, is most abundant, and can be most easily devoured in the short time that remains of their existence, the bark being then drier and harder than the leaves.

Those who buy the kermes to send to foreign parts, spread it on linen; taking care to sprinkle it with vinegar, to kill the worms that are within, which produces a red dust, which in Spain is separated from the hulk. Then they let it dry, passing it through a press, and make it up into bags. In the middle of each, its proportion of red dust, put in a little leather bag, also belongs to the buyer; and then it is ready for exportation, being always in demand on the African coast. The people of Hinojos, Bonares, Villalba, and other parts of the kingdom of Seville, dry it on mats in the sun, stirring it about, and separating the red dust, which is the finest part, and being mixed with vinegar goes by the name of paflet. The same is done with the hulls; but these have but half the value of the dust. The kermes of Spain is preferred on the coast of Barbary, on account of its goodness. The people of Tunis mix it with that of Tetuan, for dyeing those scarlet caps so much used in the Levant. The Tunisians export every year above 150,000 dozen of these caps, which yields to the Dey a revenue of 150,000 hard dollars (33,750 l.) per annum for duties; so that, exclusive of the uses and advantages of kermes in medicine, it appears to be a very valuable branch of commerce in Spain.

5. The coccus lacca, or gum-lac animal, is a native of the East Indies. The head and trunk form one uniform, oval, compressed, red body, of the shape and magnitude of a very small louse, consisting of twelve transverse rings. The back is carinate; the belly flat; the antennae half the length of the body, filiform, truncated, and diverging, ending off two, often three, delicate, diverging hairs, longer than the antennae; the mouth and eyes could not be seen with the naked eye. The tail is a little white point, ending off two horizontal hairs as long as the body. It has three pair of limbs, half the length of the insect.

This is its description in that state in which it sallies forth from the womb of the parent in the months of November and December. They traverse the branches of the trees upon which they were produced for some time, and then fix themselves upon the succulent extremities of the young branches. By the middle of January they are all fixed in their proper situa- Coccus.

situations; they appear as plump as before, but show no other marks of life. The limbs, antennæ, and setæ of the tail are no longer to be seen. Around their edges they are environed with a spiffid subpellucid liquid, which seems to glue them to the branch: it is the gradual accumulation of this liquid, which forms a complete cell for each insect, and is what is called gum lacca. About the middle of March the cells are completely formed, and the insect is in appearance an oval, smooth, red-bag, without life, about the size of a small cucanial insect, emarginated at the obtuse end, full of a beautiful red liquid. In October and November we find about 20 or 30 oval eggs, or rather young grubs, within the red fluid of the mother. When this fluid is all expended, the young insects pierce a hole through the back of their mother, and walk off one by one, leaving their exuviae behind, which is that white membranous substance found in the empty cells of the stick lac.

The insects are the inhabitants of four trees: 1. Ficus religiosa, Linnæi; 2. Ficus indica, Linnæi; 3. Plata, Hortus Malabarici; and 4. Rhamnus jujuba, Linnæi.

The insects generally fix themselves to close together, and in such numbers, that scarcely one in five can have room to complete her cell: the others die, and are eaten up by various insects. The extreme branches appear as if they were covered with a red dust, and their sap is so much exhausted, that they wither and produce no fruit, the leaves drop off, or turn to a dirty black colour. These insects are transplanted by birds: if they perch upon these branches, they must carry off a number of the insects upon their feet to the next tree they rest upon. It is worth observing, that these fig-trees when wounded drop a milky juice, which instantly coagulates into a viscid ropey substance, which, hardened in the open air, is similar to the cell of the coccus lacca. The natives boil this milk with oils into a bird-lime, which will catch peacocks or the largest birds.

A red medicinal gum is procured by incision from the plafo tree, so similar to the gum lacca, that it may readily be taken for the same substance. Hence it is probable, that those insects have little trouble in animalizing the sap of these trees in the formation of their cells. The gum lacca is rarely seen upon the rhamnus jujuba; and it is inferior to what is found upon the other trees. The gum lacca of this country is principally found upon the uncultivated mountains on both sides the Ganges, where bountiful nature has produced it in such abundance, that was the consumption ten times greater the markets might be supplied by this minute insect. The only trouble in procuring the lac is in breaking down the branches, and carrying them to market. The present price in Dacca is about twelve shillings the hundred pounds weight, although it is brought from the distant country of Assam. The best lac is of a deep red colour. If it is pale, and pierced at top, the value diminishes, because the insects have left their cells, and consequently they can be of no use as a dye or colour, but probably they are better for varnishes.

This insect and its cell has gone under the various names of gum lacca, lack, loc tree. In Bengal, la; and by the English it is distinguished into four kinds, differently denominated: for which, and their several uses, see the article Lacca.

In the figure, a represents the insect at its birth; b ditto, big with young; both the natural size. The embryo before birth inclosed in its membrane; i The coccus, with two hairs from each antenna; Ditto, with three hairs from each antenna; these three figures are magnified.

6. Coccus Polonicus, an insect which may properly enough be called the cochineal of the northern part of the world. As the cochineal loves only the hot climates, this creature affects only the cold ones. It is collected for the use of dyers; but the crops of it are much smaller, more difficultly made, and the drug itself greatly inferior to the true cochineal. It is commonly known by the name of coccus Polonicus, or the scarlet grain of Poland. That country is indeed the place where it is gathered in the greatest abundance; but it is not the only one where it is found. It is to be met with in many of the northern countries; and possibly may be found in some of the more temperate ones, where it is not yet known; as it is very much hid by nature from the eyes of common observers. It is found affixed to the root of a plant, and usually to plants of that species from thence called polygonum cocciferum; though authors have informed us of the same berry, as it is often called, being found at the roots of the mouse-ear, rupture-wort, pimpernel, and pellitory of the wall; and that it is in no other than sandy places that it is found at the roots of those plants. Breynius, in 1731, printed at Danzig a very curious account of this production, which proves it incontestably to be an animal. Towards the end of June the coccus is in a fit state for being gathered. Every one of the creatures is then nearly of a spherical form, and of a fine violet colour. Some of them, however, are not larger than poppy seeds, and others of the size of a pepper-corn; and each of them is lodged, either in part or entirely, in a sort of cup like that of an acorn. More than half the surface of the body of the animal is covered by this cup. The outside of the covering is rough, and of a blackish brown; but the inside is smooth, polished, and shining. On some plants they find only one or two of these, and on others more than forty; and they are sometimes placed near the origin of the stalks of the plants.

Breynius began his observations on the animals in this state, several of them being put into vessels of glass; and by the 24th of July, there was produced from every one of them a hexapod, or six-legged worm, with two antennæ on its head. Several of these were kept a fortnight, and showed no inclination to eat anything. They run about, however, very swiftly for some time; but then began to be more quiet, drew up their bodies shorter, and ceased to run about any longer. They were now of a purple colour; but in this state, though they did not walk about, they were subject to various contortions. At length, when they were become wholly motionless, their bodies became covered with a fine down: this was white, and formed them a perfect covering, which was sometimes of a spherical, and sometimes of an irregular figure: it was always, however, very elegant; and the downy matter plainly enough transpired out of the animal's body. The creatures remained in this state of rest, and covered with this down, for five or six days; but at the end of that time, every one of them laid more than 150 eggs. These eggs were deposited upon the paper on which the animals were placed, and were enveloped in some measure by a downy matter. When the creatures had laid all their eggs, they died; and about the 24th of August there came from every egg a small insect, which to the eye scarce seemed any other than a red point; it might, however, be observed very plainly to move about. These young animals lived about a month, wholly without sustenance. Mr Breynius was induced at first to believe, that these animals came to be in a state to produce perfect eggs, without any congress with the male; but farther observations convinced him of the error of this opinion. He saw afterwards a sort of very small flies with two white wings bordered with red, produced from several of the cocci. These flies are plainly of the same kind with the male gall-insects.

It has before been observed, that these cocci differ in size. The flies are produced by the small ones not bigger than a poppy seed; the others produce the worms before described; and one observation of Mr Breynius's affords a plain proof that these flies are the male insects of the species; since all those of the females, which had been a day or two accompanied by those flies, quickly covered themselves with down and began to lay their eggs; whereas those which had not this commerce with the flies remained in the same state, or else got only a very thin and slight covering of down, and never laid any eggs. The manner of this creature's life, however, from its being hatched, to its being found in the shape of a berry at the roots of the plants, is yet unknown: and how they assume the shape of a ball lodged in a cup, must require a nice observation to discover.

The proper time for gathering this insect, as we have already observed, is about the end of June, when it is quite full of purple juice. Those who gather it have a hollow spade with a short handle; then, taking hold of the plant with one hand, they raise it out of the ground with the tool held in the other; after which they very quickly and dexterously detach the insects, and replace the plant in the ground, where it again takes root. The coccus is then separated from the earth by means of a sieve; and in order to prevent them from turning into worms, they sprinkle them with very cold water or vinegar. Lastly, they are killed by exposure to the sun, or keeping them for some time in a warm place; but this must be done with caution, as too hasty drying would spoil the colour. Sometimes they separate the insects from the vehicles with their fingers, and form them into balls; but by this operation the price is greatly increased.

We are informed by Bernard de Bemith, from whom this account is taken, that the harvest of coccus was farmed out to the Jews by some Polish lords, who had possessions in the Ukraine; that it was used by them, as well as the Turks and Armenians, for dyeing not only wool and silk, but the tails and manes of their horses; that by its means the Turkish women dyed the tips of their fingers of a beautiful carnation; and that it was formerly used by the Dutch along with an equal quantity of cochineal, the coccus being purchased at a very dear rate; that beautiful paints may be prepared from this insect and pounded chalk, &c.

All this, however, M. Macquer supposes to have been exaggerated, as he never could produce with it any other than lilac, flesh-colour, or crimson; and he found it, moreover, vastly more expensive than cochineal, as not yielding one-fifth part of the colour. Hence this drug is almost entirely fallen into disuse, being scarce known in any of the European cities remarkable for having good dyers.