LEPIDOPTERA OF NEW YORK AND NEIGHBORING STATES 429 



15. THIODIA Hiibner 



(Pcedisca, in part; loplocama Clemens; Semasia, Hedya, Cydia, Epi- 

 notia, Enarmonia, in part) 



Similar to Eucosma; R 2 generally -nearer R t than R 3 ; costal fold absent; hind 

 wing frequently with M 3 and CUj completely united. 



Valve not strong, and shorter than in Eucosma; anal indentation usually with a 

 pronounced cluster of hairlike spines. 



The venation varies, but there is always at least some slight trace of the emar- 

 gination of the outer margin, and R 4 and R 5 are normally separate. The genus is 

 perhaps heterogeneous, being derived from more than one source in Eucosma 

 and possibly also from Epiblema. The usual food, as in those two genera, is the 

 Compositse. 



Key to the species 



1. Speculum of four rows of two black dots each. 



2. Area above the speculum (enclosed in a broken lead-colored circle) wholly 



dusted with brown 1. annetteana. 



2. Less than half the area above the speculum dusted with brown . . 2. refusana. 

 1. Speculum less complex. 



2. With a rounded central dark patch on fore wing, defined below r . 

 3. Base of fore wing pale. 



4. Ground dull pale gray, with some darker dusting and brownish shading. 



6. Exentera virginiana. 



4. Ground light ochreous 5. Exentera costomaculana. 



3. Base of fore wing, at least toward costa, dark. 



4. Base of inner margin below fold contrasting pale gray, sharply sepa- 

 rated from the black-brown costal portion 4. Epinotia lindana* 



4. Base of inner margin concolorous, or gradually shading into the light 



red-brown costal portion 3. Epinotia septemberana. 



2. No such patch. 



3. With a contrasting longitudinal white stripe in cell. 



4. Basal half of costa solidly white 13. striatana. 



4. Basal half of costa finely striate with brown ' 14. clavana. 



3. Costal fchird broadly white and more or less contrasting 15. kiscana. 



3. No longitudinal white stripes. 



4. Inner margin contrastingly pale, the pale area sharply delimited in 



the median area 6. Epinotia timidella. 



4. With a contrasting white antemedian or median fascia, preceded and 



followed with blackish. 

 5. Fascia broad and complete. 



6. Followed by a blackish fascia, the ground outwardly pale. 



1. Gypsonoma fasciolana. 



6. The whole outer half of wing dark. . . .2. Gypsonoma substitutionis. 

 5. Fascia confined to dorsal half of wing, and sometimes narrow and 



diffuse on outer side. 

 6. Apex of fore wing with bright yellow-brown overlay or iridescence. 



5. marmontana.- 



6. Apex blackish, concolorous with other dark portions of the wing. 

 7. Median dorsal white patch small and well defined, separated from 



patch at anal angle by more than its width 3. parmatana. 



7. Dorsal white patch, larger and more diffuse, separated from 

 patch at anal angle by less than its width 4. alterana. 



