BAGWORM MOTHS OF THE WESTERN HEMISPHERE 23 



of this line primarily because of the Solenobia-\ike pattern of case 

 construction and the lichenivorous feeding habit of the larvae. 



The evolutionary series culminating with the genus Coloneura 

 commences as somewhat robust insects and possesses genitalia with a 

 prominent basal development (pulvillus) of the valves. The tegumen 

 and vinculmn, in contrast to the preceding group, tend to be relatively 

 broad and the saccus in some species is reduced in length. 



The genera Thyridopteryx and Animula climax a division which 

 appears to be the most specialized of our new world psychids. Evolu- 

 tionary tendencies in this group demonstrate such features as: loss 

 of wing scales; gradual elongation of the forewings with a reduction 

 in size of the secondaries; modification of the antennae with the outer 

 segments becoming serrate; reduction in size and occasional loss of 

 the tibial armature; elongation of the male genitalia with a gradual 

 basal enlargement of the aedeagus; and other specializations. It 

 should be mentioned that the general structure of the female genitalia 

 suggests certain primitive features in this group, but this development 

 may have been retained or evolved secondarily in conjunction with 

 an increasing fecundity. Certainly this division, or at least certain 

 elements of it, has become the most successful group of psychids in 

 our hemisphere. 



Conclusions 



A total of 104 names have been referred correctly to the Psychidae 

 in the Western Hemisphere. Of this number, 74 species and 2 sub- 

 species have been considered in this revision possibly to be valid. 

 In addition, 6 unnamed larval cases, which, in part at least, may 

 eventually represent new species have been described. In the main 

 body of this work, 55 species (including 3 which are new) and 2 sub- 

 species are treated. These are grouped into 20 genera, 6 of which are 

 described for the first time. In the two appendices 19 names are 

 discussed; for this group the adult males either have not been dis- 

 covered or have not been examined by the writer. Several of the 

 names eventually may fall into synonymy, thus further reducing the 

 number of valid species. 



Readily observable morphological differences among comparable 

 stages of many species of psychids usually are very slight. Lack of 

 specific characters in the larvae is probably the result of great similarity 

 in life history: all species are case bearers throughout the larval stage 

 and tend to be general feeders. 



Speciation, with the formation of genetic barriers, likewise has 

 occurred in the adult male with little to no morphological differentia- 

 tion. The males of most species are unicolorous or possess nearly 

 transparent wings. Obviously there has been rather limited selective 



