Key to the New World Panthea

1 Antenna bipectinate (male)......................................................................... 2

– Antenna simple (female) (Note: female of P. reducta unknown) ............... 12

2 Hindwing black except fringe, scales tiny, hair-like exposing membrane, appearing glassy (label can be read through wing); Caribbean: Hispaniola (Fig. 3).......................................................................................... P. reducta

– Hindwing with white scales, or if without white scales dark scales not greatly reduced, wing opaque ................................................................................. 3

3 Small (FW length 14-15 mm); wing pattern blurred or appearing out of focus; uncus obsolete (Fig. 45); aedeagus without sclerotized cornuti, but armed with patch of many soft fleshy-appearing spines (Figs. 1, 45) ............. .................................................................................................. P. apanthea

– Larger (FW length 16 mm or more); wings with lines clear, contrasting; uncus present; aedeagus armed with 1-2 large sclerotized cornuti (Figs. 46-57)....... 4

4 Terminus of uncus bifurcate (Fig. 48) .......................................... P. gigantea

– Terminus of uncus not bifurcate; square, rounded or pointed (Figs. 46, 47, 49-57) ........................................................................................................ 5

5 Everted vesica long, narrow, 3-5 × long as wide (Figs. 54-56)...................... 6

– Everted vesica short, bulbous, 1-2 × long as wide (Figs. 46-53) ................... 8

6 Vesica with large bent or curved terminal cornutus (Fig. 56); sw USA .......... ......................................................................................................... P. greyi

– Vesica with large straight terminal cornutus (Figs. 54-55); eastern USA and Canada ....................................................................................................... 7

7 Vesica with second smaller cornutus near base of vesica (Figs. 55, 57), southeastern USA (Fig. 71) .................................................... P. furcilla australis

– Vesica without second cornutus (Fig. 54); eastern USA and Canada (Fig. 71) (Note: specimens from zone where furcilla and australis meet show intermediate characters) ............................................................... P. furcilla furcilla

8 Vesica with large curved claw-like basal cornutus and finger-like diverticulum with a small straight terminal cornutus (Fig. 50)..................... P. virginarius

– Vesica without finger-like diverticulum (Figs. 46-49) (Note: some specimens of virginarius from Wyoming and southern Idaho may have a greatly reduced diverticulum with a very small or obsolete spine) (Fig. 51).......................... 9

9 Vesica with two large, curved, approximately equal-sized cornuti (Fig. 59) ... ................................................................................................ P. guatemala

– Vesica with two prominent cornuti, one much smaller in size (Figs. 46; 52- 53)............................................................................................................ 10

10 Vesica with one short curved cornutus and one long, thin, straight or recurved cornutus; clasper simple, not scoop-shaped or forked (Figs. 52-53) 11

– Vesica with large basal and small terminal cornutus; large scoop-shaped clasper (Fig. 46) ............................................................................. P. judyae

11 Wings with prominent white areas (Figs. 36-38); eastern and boreal North America (Fig. 71).......................................... P. acronyctoides acronyctoides

– Wings without prominent white areas, or if white area present, confined to small areas of outer edge of FW postmedian line and anal angle of HW (Figs. 40-43); Rocky Mountains and foothills (Fig. 71) ........................... .................................................................................. P. acronyctoides nigra

12 Sterigma vestigial or obsolete (Fig. 58); sw USA ......................... P. apanthea

– Sterigma well developed (Figs. 59-68)....................................................... 13

13 Corpus bursae with thick-walled opaque upper and thin-walled translucent lower sections (Figs. 65-68)....................................................................... 14

– Corpus bursae single, an oval or oblong, thin-walled translucent sac (Figs. 59-64) ...................................................................................................... 16

14 Ductus bursae narrow, finely folded or “corrugated,” expanding abruptly to corpus bursae (Figs. 65-67); eastern USA and Canada .............................. 15

– Ductus bursae wider, with large folds, widening gradually and with folds extending onto upper section of corpus bursae (Fig. 68); sw USA (Fig. 71)...... ......................................................................................................... P. greyi

15 Ductus bursae strap-like, few twists and folds (Fig. 67); east and se USA (Fig. 71)......................................................................... P. furcilla australis

– Ductus bursae not strap-like, with many finer “corrugated” folds (Fig. 65); northeastern USA and Canada (Fig. 71) (Note: specimens of ssp. australis and furcilla show intermediate characters where the ranges meet) ........................ ........................................................................................ P. furcilla furcilla

16 Sterigma massive, heavily sclerotized (Figs. 58-61).................................... 17

– Sterigma not massive, only moderately sclerotized (Figs. 62-64) ............... 19

17 Ductus bursae heavily sclerotized to or almost to corpus bursae (Fig. 61)...... ................................................................................................ P. guatemala

– Ductus bursae with heavily sclerotized part extending no more than half way to corpus bursae (Figs. 59-60)................................................................... 18

18 Ductus bursae between sterigma and corpus bursae narrow; corpus bursae tear-drop or oval shape (Fig. 59); FW length less than 25 mm ....... P. judyae

– Ductus bursae below sterigma wide; corpus bursae oblong (Fig. 60); FW length greater than 25 mm .......................................................... P. gigantea

19 Ductus bursae slightly curved, smooth, with expanded rim at ostium (Figs. 63-64) ..................................................................................................... 20

– Ductus bursae straight, wrinkled, without expanded rim at ostium (Fig. 62) ............................................................................................... P. virginarius

20 Wings with prominent white areas (Figs. 36-38); eastern and boreal North America (Fig. 72) ......................................... P. acronyctoides acronyctoides

– Wings without prominent white areas (Figs. 40-43); Rocky Mountains and foothills (Fig. 69) (Note: specimens of acronyctoides show intermediate characters in central Alberta) ........................................... P. acronyctoides nigra