NORTH AMERICAN LASPEYRESIINAE AND OL.ETHREUTINAE 129 



A compact genus represented outside of North America as far as 

 I know only by a few Asiatic species. It derives directly from Oleth- 

 reutes. The chief character separating it from that genus is the 

 strongly developed basal lobe on the hind wing of the male. This is 

 a prolongation and folding over of the membranous area of the wing 

 back of vein la, including within the fold a chitinous ridge morpho- 

 logically homologous with that upon the inner margin of the male 

 hind wing in Olethreutes and several other Olethreutine genera. The 

 mere presence or absence of such a lobe (it is a secondary character 

 that has been separately acquired in at least three other genera) 

 would not be a sufficient character for either separating or bringing 

 together species in generic grouping, did other facts not justify such 

 a proceedure. As it is, the character seems to be a good one ; that is, 

 for separating species with such a lobe from those without it, not, 

 however, for grouping together all species having it. 



Loxotemna^ CymoloTnia, and Eccofsis each has a lobe similar to 

 that of Exartetrm; but each is a good genus. On genitalia Loxoterma 

 Busck (type, Tortrix latifasciana Haworth, fig. 390), might go very 

 well with Exartema. It differs strikingly, however, in venation (hav- 

 ing veins 3-4 of hind wing separate). Cymolomia Lederer (type, 

 Scio/phila hartigiana Ratzeburg) also differs in venation, having 

 3-4 of hind wing stalked, a character which would place it outside 

 the subfamily did not genitalia and habitus show it to be a true 

 Olethreutine. Its genitalia are quite different from those of Exar- 

 tema (see fig. 396). Eccopsis Zeller (type, Eccopsis waKlbergiana 

 Zeller) is at once differentiated by the much produced and strongly 

 chitinized socii of its genitalia (figs. 57, 397) and the branching of 

 the upper internal vein of cell of fore wing from between 9 and 10. 

 I have noticed what appears to be a tendency to this latter develop- 

 ment in one species of Exartema {inonetiferanum Riley, see p. 135) ; 

 but here I think the occasional branching of the internal vein from 

 between 9-10 is a mere freak occuring in very few specimens. I have 

 never noticed it in any other species of Exartema,' and wherever else 

 it occurs it seems to be a consistent character of real generic value. 



I am holding the genus Exartema because I believe it represents 

 a natural group. All the species with the exception of a few have 

 strikingly similar male genitalia of a peculiar type. The exceptional 

 species (those of Group C) correspond in genitalia rather closely 

 with certain species of Olethreutes and probably represent the base 

 of the Exartema line where it branches from the main Olethreutes 

 stem. There is nothing to indicate that the group had other than a 

 single point of origin, or that its developmental tendency is in more 

 than one direction from that point. General habitus shows the 

 several species to be closer to each other than to any Olethreutinae 



