1913] Wing Veins of Membracidce 81 



occurring along the first anal vein. There are few cross- veins 

 but those present are remarkably constant. The wing may or 

 may not be covered by the pronotum, but in no case is it to be 

 considered in the sense of an elytron. 



The hind wing is not nearly so dissimilar to the fore wing as 

 is the case in most insects. C. W. Woodworth in the "Wings 

 of Insects"^"'' remarks that "the hind wings of most of the 

 families of Homoptera have more nearly kept pace with the 

 front wings in their specialization, than have those of the 

 Heteroptera". This is certainly true of the Membracidas. 

 There are fewer veins and cells in the hind wing than in the 

 fore but their homologies are evident. 



Both wings are characterized by the strongly scalloped 

 margin of the veined surface and the comparatively narrow 

 terminal membrane. 



Like most of the other Hemiptera, the wings of the Mem- 

 bracidae are specialized by reduction, but the reduction has not 

 been carried so far as in most of the other families of this order. 

 This reduction has been carried on in two ways, viz. : by atrophy 

 and by coalescence. Reduction by atrophy is shown by costa in 

 both wings. Coalescence, in turn, has been accomplished by two 

 methods- — by coalescence from the base towards the margin, 

 as illustrated by cubitus, and by the anastomosis of veins in 

 the center of the wing followed by their subsequent divergence, 

 as shown in the case of radius four-plus-five plus media one- 

 plus-two. No cases have been noted of coalescence from the 

 margin proximad. 



However, no hint of the particular veins in which this 

 specialization occurs is given by the venation of the adult 

 wing, and it is only by following the nymphal structure, trachea 

 by trachea, and branch by branch, that the actual solution can 

 be reached with any degree of accuracy. 



NYMPHAL TRACHEATION 



A study of the most general characteristics of the nymphal 

 tracheation may well be made before proceeding to the consider- 

 tion of the minutia. In the fore wing (Fig. 2), it will be noted 

 that there are five main tracheae. Beginning at the anterior 

 margin, the first is unbranched and extends almost to the tip 

 of the wing. The second appears two-branched and the 

 posterior branch anastomoses for some distance with the ante- 



13. Univ. of Cal. Publ., Ag. Ex. Sta. Tech. Bull. Ent., Vol. I, No. 1, p. 124. 



