The Penny Cyclopædia of The Society for the Diffusion of Useful Knowledge.
Fuego, Tierra Del - Haddingtonshire.
London: Charles Knight and Co., 22, Ludgate Street.
Coccus Cacti, magnified,. a, the male, b, the female.
GALLINSECTA (Latreille), COCCIDÆ. (Leach), a family of insects placed by Latreille and others at the end of the Homoptera. These insects apparently have but one joint to the tarsi, and this is furnished with a single claw. The males are destitute of rostrum, and have two wings, which when closed are laid horizontally on the body the apex of the abdomen is furnished with two setæ. The females are apterous, and provided with a rostrum. The antennæ are generally filiform or setaceous.
The insects belonging to this family live upon trees or plants of various kinds : they are of small size, and in the larva state have the appearance of oval or round scales, which are closely attached to the plant or bark of the tree they inhabit, and exhibit no distinct external organs. At certain seasons, when about to undergo their transformation, they become fixed to the plant, and assume the pupa state within the skin of the larva. The pupa of the males have their two anterior legs directed forwards, and the remaining four backwards ; whereas in the females the whole six are directed backwards. When the males have assumed the winged or imago state, they are said to issue from the posterior extremity of their cocoon.
In the spring time the body of the female becomes greatly enlarged, and approaches more or less to a spherical form. In some the skin is smooth, and in others transverse incisions or vestiges of segments are visible. It is in this state that the female receives the embraces of the male, after which she deposits her eggs, which are extremely numerous. In some the eggs are deposited by the insect beneath her own body, after which she dies, and the body hardens and forms a scale-like covering, which serves to protect the eggs until the following season, when they hatch. The females of other species cover their eggs with a white cotton-like substance, which answers the same end.
Upwards of thirty species of the family Coccidad&elig;, or Gallinsects, are enumerated in Mr. Stephen's Catalogue of British Insects ; several of these however have undolibtedly been introduced with the plants they inhabit, and to which they are peculiar.
Many of the exotic Cocci have long been celebrated for the beautiful dyes they yield. The Coccus Cacti of Linnaeus may be mentioned as an instance. The female of this species is of a deep brown colour, covered with a white powder, and exhibits transverse incisions on the abdomen. The male is of a deep red colour, and has white wings.
This insect, which when properly prepared yields the dye called cochineal, is a native of Mexico, and feeds upon a particular kind of Indian fig, which is cultivated for the express purpose of rearing it. [Cochineal.]
Coccus Ilicis, an insect found abundantly upon a small species of evergreen oak (Quecus coccifera), common in the south of France, and mauy other parts, has been employed to impart a blood red or crimson dye to cloth from the earliest ages. (Introduction to Entomology, by Kirby and Spence, vol. p. 319.)
Coccus Polonicus is another species which is used in dyeing, and imparts a red colour. It is now chiefly employed by the Turks for dyeing wool, silk, and hair, and for staining the nails of women's fingers. (Kirby and Spence, vol. i.,p. 320.)
But we are not only indebted to the Coccus tribe for the dyes they yield : the substance called Lac is also procured from one of these insects (the Coccus Lacca). This species inhabits India, where it is found on various trees in great abundance. When the females of this Coccus have fixed themselves to a part of the branch of the trees on which they feed (Ficus religiosa and Indica, Butea frondosa, and Rhamnus Jvijuba), a pellucid and glutinous substance begins to exude from the margins of the body, and in the end covert) the whole insect with a cell of this substance, which when hardened by exposure to the air becomes lac. So numerous are these insects, and so closely crowded together, that they often entirely cover a branch ; and the groups take different shapes, as squares, hexagons, &c., according to the space left round the insect which first began to form its cell. Under these cells the females deposit their eggs, which after a certain period are hatched, and the young ones eat their way out.' (Kirby and Spence, vol. iv., p. 142.)