10 THE COCDIDAE 



The transverse constrictions of the body of the female in each 

 succeeding nymphal stage after the first become more and more 

 obscure, until in the adult females of many species the coriae 

 are wanting or so indefinite that it is impossible to determine, 

 except in a general way, the caudal extent of the head. The eyes 

 are represented by a single ocellana on each side of the head or 

 are wanting. The body increases in size and becomes plumper so 

 that the antennae and legs do not appear so long and large and 

 out of proportion to the remainder of the body. The adult females 

 of many coccids are without legs and frequently, where they are 

 retained as in most Coccinae, they do not project beyond the 

 lateral margin of the body. 



The female like the male may pass through a quiescent period 

 and, as in the case of the male, it varies greatly in length. The 

 legs and antennae which are wanting in most of the nymphal 

 stages of Margarodes are regained in the adult. The function of 

 the quiescent period is entirely different, not only for the making 

 over of the organs and tissues of the body, but for the production 

 and laying of eggs or for the giving birth to young. In a few 

 cases, as the Ortheziinae, the female never becomes quiescent. She 

 excretes a sack of wax which remains attached to her body. The 

 eggs are deposited in this sack, which is carried about until the 

 eggs hatch and the young nymphs emerge from the free and open 

 end. In the great majority of the species, generalized as well as 

 specialized, the female forms a mass or sack of wax or a scale which 

 is attached to the host-plant. This wax, which varies greatly in 

 consistency, is either interposed between the body of the female 

 and the host-plant or forms a covering over her body or completely 

 encases her body in a flocculent or dense mass. It is the color of 

 the wax, which is generally white, that makes the individuals or 

 colonies of coccids conspicuous and attracts attention to their 

 presence. 



The members of the family Coccidae are of great economic 

 importance because of the injuries that they do to growing plants. 

 They subsist upon the sap which they obtain by means of the 

 tube formed by the close apposition of the bristle-like mandibles 

 and maxillae. Even if the great diversity and complexity of their 

 metamorphosis, their complicated anatomy, and the different ways 

 in which they produce substances useful to man were not con- 

 sidered of sufficient importance to warrent spending so much time 

 on the study of these insects, sufficient reason is found in the great 

 number of injurious species belonging to this family and the 

 enormous amount of damage which they do. 



