2 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 119 



in which he defined several genera and associated species (formerly in 

 Gelechia) with each genus. Only one or two representatives of each 

 genus were figured; thus, most of the names, even though correctly 

 associated generically, are not recognizable as species in that work. 

 The result is that most of the described Nearctic gelechiids cannot be 

 determined from the existing Hterature. 



Failm-e to associate species with earlier names has led nearly all 

 workers to describe and redescribe several species while leaving 

 closely related, vahd species unnamed. To avoid this situation I 

 have examined nearly all of the existing type specimens and before 

 completion of this series of papers plan to study all of them. Some 

 types, particularly those of Chambers, are no longer extant. An 

 attempt will be made to associate his names with species whenever 

 possible. 



This paper on the Lita group is the first of a series, the purpose of 

 which is to make known the described and undescribed Nearctic 

 gelechiids, to illustrate each species, and to present keys for identifi- 

 cation of the genera and species. The most useful part of the work 

 will appear last: the summary of major groups and keys to genera. 

 However, until the fauna is moderately well known, generic definitions 

 will continue to change. 



Because of their small size, Microlepidoptera, in general, have 

 been poorly collected; thus, distributional information usually is 

 inadequate to give a complete picture of the geographic range of any 

 species. One serious ramification of this point is that clinally variable 

 character systems may remain unrecognized, and thus two or more 

 populations may be given names when they represent discontinuous 

 samples of a species rather than samples of two or more species. 

 Variation appears to be the rule in the Lepidoptera and may occur in 

 maculation, coloration, vestiture, size and shape of abdominal sclerites, 

 width of antennal segments, or characters of the genitalia. However, 

 suspected or anticipated variation cannot be confirmed on the basis of 

 few specimens from widely scattered localities. Until much more 

 diligent collecting is done for nearly all major Nearctic locality types, 

 works of this nature are necessarily sketchy and subject to fiu-ther 

 revision. 



As would be anticipated for a relatively large family, the larval 

 habits are moderately diverse; but on the whole, living plant tissues 

 are attacked. Some species are leaf or needle miners for all or part 

 of the larval stage; many are leaf rollers or tiers; some are stem borers 

 or gall formers; some feed in developing seed heads of composites; 

 some are external feeders; and some feed on dried seeds. Normally, 

 some shelter is present, whether it be a silk webbing, a gall, or a 

 leaf roU. A few species, such as the pink boUworm [Pectinophora 



