52 . William T. M. Forbes 



91. Accessory cell very large, extending halfway to base of fore wing (fig. 106) ; 

 hind tibiae with a large mass of loose hair Tischeriidae (p. 145) 



Larva 8 

 1. Thoracic legs wanting or reduced to fleshy swellings, without chitinized seg- 

 ments 2 



1. Thoracic legs developed, with chitinous segments 8 



2. Body fusiform, thickest at middle, head small with closed front (separated 



from the vertex by the epicrania) Incurvariidae (Prodoxus) (p. 72) 



2. Body cylindrical or flattened; when somewhat fusiform with front reaching 



vertex 3 



3. Head with six small ocelli on each side 4 



3. Head with two ocelli on each side, front not reaching vertex. 



Heliozelidae (p. 225) 



3. Head with a single large ocellus on each side, or none 5 



4. Abdomen with rudimentary ventral prolegs on third to sixth segments, bear- 



ing hooks Tischeriidae (p. 145) 



4. Abdomen without prolegs on sixth segment Gracilariidae (p. 161) 



5. Ocellus frontal, front triangular .Eriocraniidae (p. 64) 



5. Ocellus lateral, front quadrangular 6 



6. Front widest at posterior end, body normally depressed, prolegs on third to 



fifth segments of abdomen when present Gracilariidae (p. 161) 



6. Front widest at anterior end, body cylindrical; rudimentary prolegs on second 



to seventh segments of abdomen or none 7 



7. Body normal, five times as long as thick, normally with prolegs. 



Nepticulidae (p. 79) 



7. Body very slender, ten times as long as thick, without prolegs. 



Opostegidae (p. 160) 



8. Setae replaced by large, ovate scales, arranged in pairs. . . Micropterygidae (p. 62) 



8. Setae normal 9 



9. Crochets wanting, prolegs rudimentary or absent 10 



9. Prolegs at least represented by rudimentary crochets 13 



10. Front extending obviously to vertex; small species Coleophoridae (p. 202) 



10. Front not extending to vertex (except when vertex is represented by a very 



narrow slit ) 11 



11. Head completely retracted, body frequently with spines or secondary hair, 



the primary setae obsolete; body with obscure incisures, usually with con- 

 spicuous pits Eucleidae (p. 102) 



11. Head normally exposed; body with primary setae only, which are usually dis- 



tinct ; with strong incisures 12 



12. Setae iv and v distant on abdomen; prolegs present, though without hooks 



(fig. 51 ) Incurvariidae (Tegeticula) (p. 72) 



12. Setae iv and v adjacent (fig 174) ; prolegs absent A few Gelechiidae (p. 255) 



13. Body without secondary or tufted setae, tubercle vi single; vii of three setae 



at most, unless the proleg has a multiserial circle of hooks, when it may 

 have four setae; sometimes with a couple of dorsal subprimary setae.... 14 



13. Body with tufted or secondary hair; at least two setae on tubercle vi on sixth 



segment of abdomen, or with additional setos on proleg 48 



14. Sixth segment of abdomen without a proleg Gracilariidae (p. 161) 



14. Sixth segment of abdomen with a proleg, the more anterior segments some- 



times without 15 



15. Hooks of prolegs arranged in a circle or ellipse (sometimes interrupted), or in 



transverse bands 16 



8 Modified from the key in The Classification of Lepidopterous Larvae, by S. B. Fracker Illinois Biolog- 

 ical Monographs, vomme 2. number 1. 



