240 THE STUDY OF INSECTS. 



The rolled leaves serve the Tortricid larvae not merely 

 as homes but also as food, for they feed upon the enclosed 

 portions. Sometimes several leaves are used by a larva, 

 but more often only one, or in many cases merely a tip or 

 one edge of a leaf is used. Some species cut a slit in a leaf 

 and roll only one part of it. They also differ greatly as to 

 the extent to which the leaves are rolled. Some species are 

 gregarious, an entire brood making a common nest. During 

 the latter part of the summer and in the autumn these 

 rolled leaves can be found on almost any tree or shrub. 



In nearly all cases entomologists in naming Tortricids 

 have formed the specific name with the ending -ana; so 

 that the form of the name indicates the family to which the 

 insect belongs. 



More than four hundred North American species of 

 Tortricids are known. The superfamily includes three fam- 

 ilies, which can be separated by the following table : 



A. With a fringe of long hairs on the basal part of vein VII of the 

 hind wings, on the upper side of the wing. Do not mistake a 

 bunch of long hairs arising from the wing back of vein VII for 



this fringe, p. 240 GRAPHOLITHID.E. 



AA. Without a fringe of long hairs on the basal part of vein VII of 



the hind wings. 

 B. Vein VIL of the fore wings arising from the outer fourth of the 



discal cell, p. 243 CONCHYLIDS. 



BB. Vein VI I 2 of the fore wings arising from a point before the 

 outer third of the discal cell, p. 244 TORTRICIDS. 



Family GRAPHOLITHID.-E (Graph-o-lith'i-dae). 

 The GrapJiolitJiids (Gra-phol'i-tJiids). 



These moths are easily distinguished from other Tortri- 

 cids by the presence of a fringe of long hairs on the basal 

 part of cubitus of the hind wing. To this family belong 

 nearly two thirds of our species of Tortricids. The follow 

 ing are some of our more common species : 



