SUBFAMILY LECANHNAE 157 



absolutely true for the dorsal and more often the ventral aspect 

 is covered more or less with mealy wax. These species are, 

 however, truly naked when compared with representatives of such 

 genera as Ceroplastes which is completely encased in a mass of 

 wax or Pulvinaria which excretes a large white doughy mass of 

 wax several times as long as the body or as Takahashia where the 

 wax excreted is a tail several inches long. In Platinglisia 

 the waxy covering is glassy, in Signoretia woolly, and in Eriopeltis 

 a closely felted sac. 



The body of the adult female in those genera where the body 

 is said to be naked, as Lecanium, is fairly uniform in appearance. 

 This form of body has been taken as the type for the following 

 description. The general outline is that of an elongate oval figure, 

 passing through the various stages to that of a rotund figure or one 

 that is almost or wholly globular. The two surfaces of the body are 

 near together, the dorsal convex and the ventral concave. This 

 gives the characteristic scoop-like figure of the shell of a tortoise 

 or of a steel war helmet and hence the vernacular name of the 

 group. Those species that are encased in a mass of wax, varying 

 in amount and thickness with the species and those species that 

 form large ovisacs depart more or less from this general form. 

 Those that form ovisacs have the body flat and both surfaces more 

 or less convex and approximate the condition of a typical eriocoacid 

 and so far as form is concerned represent the generalized end of 

 the series of genera. The person with an eye for judging form 

 will note, however, that even in these genera, there is a striking 

 resemblance between the wax excreting and the naked species. A 

 prominent feature of most of the naked species is the strongly con- 

 cave ventral aspect of the body of the older nymphal stages and of 

 the adult female. 



A noticeable feature of the body is the entire absence of any 

 indication of segmentation in the adult female. The only meajis of 

 identifying the extent of the three primary regions is through the 

 presence and articulation of the antennae, rostrum, legs, and the 

 position of the thoracic spiracles. 



The typical form of the body, shaped like a tortoise-shell, 

 makes the margin of the body sharp and prominent, forming a 

 distinct margin. This margin is generally fringed with setae 

 which vary considerable in number, size, and shape. They are 

 known as the marginal setae. While in many species these setae 



