38:2 THE coccidae 



light yellowish in color, but may be blackish or brownish. The 

 ventral scale varies greatly in consistency from a delicate tissue- 

 like sheet to a rather thick pellicle. It usually remains attached 

 to the host-plant and is in most cases so delicate that the ventral 

 portion of the exuvia is generally lost. The scales are more or 

 less convex or obconical, the exuviae and cicatrix being placed on 

 the highest part of the scale. This arrangement gives the scales 

 quite an armored shield-like appearance from which has been de- 

 rived many of their scientific names as well as the common name of 

 the Armored Scales, applied to the subfamily as a whole. This 

 structure is typical, however, only of the scales of the tribe 

 Aspidiotini. 



The scale of the male is similar in shape, appearance, and 

 color to that of the female. They differ from the scales of the 

 adult female only in having a single exuvia and their much smaller 

 size. The scale of the male is so similar to that of the first stage 

 female that it is generally quite difficult to differentiate them and 

 frequently this can onl}^ be done by examining the insects under 

 the scales. The scales of those males having females with oval 

 scales are frequently also oval. 



The body of the adult female is located under the central 

 part of the scale. It is typically triangular or deltoid in shape, 

 broadest across the thorax or head, the exact location varying with 

 the species. "When widest across the head, the cephalic end of the 

 body is frequently very broad and sometimes truncate. The body, 

 even when fully expanded, is rarely twice and in most species is 

 about one and one-half times as long as wide, but, when the seg- 

 ments of the preabdomen and pygidium are retracted or telescoped 

 as is the usual condition in the dead and dried individuals, the 

 body is not any longer than wide and is frequently even wider 

 than long. In those species that lay eggs the retraction of the 

 caudal end of the body makes a place for the eggs which are usually 

 mixed with the fine pulverulent wax excreted by the genacerores. 

 The antennae are typical of the form found in the subfamily. 

 Each consists of a small tubercle bearing a long curved seta sur- 

 rounded by one or more much shorter ones, usually about four. 

 The antennae are often greatly reduced in size or wanting. The 

 segmentation of the thorax is generally obscure. There are a few 

 genera as Selenaspidus and its near allies in which there is a deep 

 constriction between the mesothorax and metathorax. In fully 

 expanded individuals the segmentation of the preabdomen is fairly 

 distinct and the lateral indentations are rather prominent. The 



