SUBFAMILY COCCINAE 101 



season consist in great part of young nymphs and molted skins 

 which are consequently, not nearly so rich in coloring matter. A- 

 pound of the dead females contains about 70,000 individuals. 

 There are three grades of cochineal. The silver cochineal, which 

 is greyish in color in which the furrows of the body are said to be 

 covered or filled with a whitish bloom of fine down, is the best 

 grade. This bloom is undoubtedly the wax excreted by the female 

 after her removal from the host-plant and before her death. The 

 other grades are black cochineal which is dark reddish brown and 

 is destitute of the bloom and granilla which is an inferior grade 

 collected from uncultivated or wild plants. 



The living adult females of the genus Coccus are between two 

 and three millimeters in length. The body is elongate oval in 

 outline. The antennae are short and inconspicuous, the six or 

 seven segments consisting of short chitinized rings connected by 

 coriae of about the same length. They do not project beyond the 

 lateral margin of the body. The legs are short and stout, similar 

 in form. The femur of each leg is as long as its tibia and tarsu'^ 

 together. The rostrum consists of two segments. The thoracic 

 spiracles are four in number, small, and ventral in position. The 

 abdominal spiracles are wanting. The anus and vulva are incon- 

 spicuous. All portions of the external cuticle of the body bears 

 bluntly truncated setae or tubercles as they are called which are 

 very characteristic in form. The number of these setae present 

 and their length and breadth varies with the species. There are 

 a number of minute cerores arranged in groups of varying size 

 scattered among the truncated setae. 



The females, which are dark crimson in color, when they reach 

 maturity, excrete a mass of white cottony threads of wax. The 

 insects are either completely covered hy this mass of wax or rest 

 upon its surface. The eggs are deposited within the mass. 



The nymphs of the first stage are similar in shape to the adult 

 females, elongate oval in outline, and dark crimson in color. They 

 have long legs that project beyond the sides of the bodj^ The 

 antennae, which also project beyond the margins of the body, 

 consist of six segments with distinct constrictions between them. 

 The dorsal aspect bears six rows of truncated setae, a longitudinal 

 row along each lateral margin and four between them. There is a 

 single transverse row on each abdominal segment and probably twc 

 for each thoracic segment and the head. The truncated setae are 

 wanting on the ventral aspect. The females of the second nymphal 



