COCCUS, a genus of insects belonging to the family Coccid, of the order Hemiptera. 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. They 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 transforma tion, they become fixed to the plant, and assunae the pupa state within the skin of the larva, The pupa of the male has the two anterior legs directed forwards, and the remaining four backwards ; whereas in the female the whole six are directed backwards. 1Vhen 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) incisionslor;vestiges of segments are visible. It is in this state that the female receives the embraces of the male, after which she deposits lier eggs, which are extremely numerous. ln some, the eggs aro 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 tho following season, when they hatch. The females of other species cover their eggs with a whito cotton-like substance, which answers the same end. Of the species of this genus known in S. Asia, are the C. cacti, the cochineal insect, the C. lacea, which yields the stick-lac of co mem, and the C. maniparus of Arabia, that punctures the Tamarix gallica, and causes the exudation of the Arabian manna. There are two varieties of Coccus cacti, the true Grana fina, and the Grana sylvestris; and, after prolonged efforts on the part of Drs. James Anderson and Barry of Madras in 1795, the C. sylvestris, or wild species of the cochineal insect, was introduced into Bengal by Captain Neilson of II.M. 74th Regiment. It throve rapidly on the Cactus Indica, the indigenous opuntia, the country Nopal, and between 1800 and 1807, 74,633i lbs. of the cochineal, amounting
to 142,916 rupees in value, were shipped to Eng land, but at a loss, as the wild species was found greatly inferior to the true. The cochineal insect wa.s introduced into Java about the year 1825 as a Government expetiment, and apparently with more success in its production than in British India, for so long ago as 1844 it was exported from Batavia to the estimated value of 93,319 guilders. The species introduced into India swarms at certain seasons, and settles on one of the species of cactus, which they immediately destroy. The whole neighbourhood of Ilemanabad was surrounded with prickly pear, but disappeared in 1865, under one of these sNN arms.
The fine cochineal insect differs from the wild not only in size, but also in being mealy and covered with a white powder ; while the wild one is enveloped in a thick cottony down, which causes its value to diminish greatly, it being im possible to separate it from the insect in the pre paration of the dye ; the females only yield dye. It is the cottony covering which enables the wild kind to stand the vicissitudes of clitnate, while the fine or domesticated kind require to be kept under cover during the rainy season, and sheltered from high winds, as they early in their growth throw off the cottony covering.
The fine cochineal insect lives on several culti vated kinds of cactus without thorns of which the Cactus cochinillifer has been introiluced into India. It will not grow on the wild prickly pear.
There are three periods of life of the cochineal insect. It is viviparous, and at its birth is a mere speck, and at that time no difference can be detected by a microscope between the sexes ; they are all equally active, seeming to profit eagerly of the short period during which motion is allowed them. After a few days they attach themselves to the cactus plant, and from that moment the female never quits her bold. A cottony coat grows over her, which falls off in 13 to 15 days. This is the first period.