CHAPTER XVIII 

 ORDER HOMOPTERA* 



Cicadas, Leaf hoppers, Apkids, Scale-bugs, and others 



The winged members of this order have four wings, except in the family 

 Coccidce; the wings are of the same thickness throughout, and usually are 

 held sloping at the sides of the body when at rest. The mouth-parts arc 

 formed for piercing and sucking; the beak arises from the hind part of the 

 lower side of the head. The metamorphosis is incomplete except in some highly 

 specialized forms. 



Although the Homoptera is a well-defined order, the families of which 

 it is composed differ greatly in the appearance of their members. For 

 this reason there is no popular name that is applied to the order as a 

 whole. 



The wings of the Homoptera are usually membranous, but in some 

 the front wings are subcoriaceous. In these cases, however, they are of 

 quite uniform texture throughout, and not thickened at the base as in the 

 Hemiptera. 



Many wingless forms exist in this order; in the family Coccidas the 

 females are always wingless; and in the family Aphididas the males may 

 be either winged or wingless, while usually the sexually perfect females 

 and certain generations of the agamic 

 females are wingless. In the Coccidce 

 the males have only a single pair of 

 wings, the hind wings being represented 

 by a pair of club-like hal teres. 



In the Homoptera the front part of 

 the head is bent under and back so that 

 the beak arises from the hind part of the 

 lower side of the head. 



The mouth-parts are formed for 

 piercing and sucking. The piercing 

 organs consist of four long, bristle-like 

 setae, the mandibular and maxillary 

 setas; these are enclosed in a long, 

 jointed sheath, which is the labium. 

 The labium and the enclosed setas con- 

 stitute what is commonly termed the 

 beak. 



As an example of the homopterous ««• maxill] ,7 f , seta A ; , c \ c \ y t pe ^ l \ labi T, ; ,'A epi ; 



... * r pharynx. (After Marlatt with changed lettering.) 



type ot head and mouth-parts those of a 



cicada are probably the most available, on account of the large size of these 

 insects and the comparative ease with which the parts of the head can be 

 distinguished. Figure 181 represents a front view of the head. 

 * HomSptera: homos (6/j.os), same, pteron (irrepop), a wing. 



IOQ 



Fir,. 181. — Head of cicada: mi. rmndibularseta; 



