SUPERFAMILY JASSOIDEA 105 



larval and i)iipal stages they do not secrete any such frothy 

 masses. 



Superfamily Jassoidea. — The superfamily Jassoidea in- 

 cludes several subdivisions of considerable importance. They 

 abound particularly on low vegetation, and some are grass 

 feeding, others tree inhabiting. They difl'er from the Ful- 

 goridte in the more specialized and compact head and 

 thoracic region and in the more distinctive character of the 

 hind tibia which is more prismatic in form and with two 

 rows of spines and without any circle of spines at the ti]). 

 The subdivisions are separated by means of the venation 

 of the wings, and by the head parts. There are four fairly 

 distinct families. 



The life histories are somewhat complex. Some species 

 have a single brood each year, others two, others apparently 

 three. Some hibernate as adults, many as eggs, some 

 apparently in partially developed nymphal stages. Some 

 of the striking examples are the grass leafhoppers, forms 

 that live continually in the grass and suck the sap, causing 

 a considerable decrease in the crop, reducing quantity and 

 quality of the nutritive contents of the grass leaves. In 

 some the individuals are extremely abundant, one to two 

 millions to the acre. 



The life histories are much the same throughout the group, 

 but not many have been worked out in detail. The group 

 stands as one of the most specialized of the Homoptera 

 that have the primitive condition of the mouth parts. 



The term vertex is used for the upper surface of the 

 head between the eyes and extending to the front border, 

 which may merge gradually into the front or the face. The 

 frons, or front, is the part of the face lying between the 

 sutures and extending down nearly to the lower border. 

 At the sides of this are portions next the eyes, which are 

 termed the cheek, and below the front a part called clypeus, 

 at the sides of which are the lorse. The central part of the 

 body which bears the wings and legs is termed the thorax, 

 and the upper portion of the first segment is known as the 

 pronotum. The front wrings are termed elytra and are 



