Lasionycta leucocycla

Key to the L. leucocycla species-group

1. Forewings and hindwings mottled gray without other color scales, all forewing lines and spots including claviform spot present, AND ventral hindwing nearly uniform gray except for faint dark discal spot and postmedial line (L. perplexa and L. subfuscula sub-groups (Figs 106–122))............................... 2

– Forewings and hindwings otherwise; if forewing gray then claviform spot absent, hindwing lighter colored, OR ventral hindwing with dark marginal band in addition to discal spot and postmedial line.................................. 10

2. Male.......................................................................................................... 3

– Female....................................................................................................... 6

3. Antenna broadly bipectinate, total width greater than 4× width of shaft..................................................................................................... L. subfuscula

– Antenna less than 4× width of shaft........................................................... 4

4. Antenna bipectinate, total width greater than 2.5× width of shaft.................................................................................................................. L. perplexa

– Antenna biserrate, less than 2.1× width of shaft......................................... 5

5. Ventral hindwing lighter gray than ventral forewing, hindwing discal spot darker than postmedial line (Figs 110–112); occurring north of southern Washington............................................................................ L. perplexella

– Ventral hindwing and forewing similar in color, hindwing discal spot similar in darkness to postmedial line (Figs 113–115); occurring from southern Idaho and Beartooth Plateau on Montana-Wyoming border southward (including California)................................................................... L. subalpina

6. Corpus bursae angled 30° to left from ductus bursae............... L. subfuscula

– Corpus bursae and ductus bursae nearly straight........................................ 7

7. Occurring south of southern Idaho and Beartooth Plateau (including California)........................................................................................................ 8

– Occurring in Oregon or farther north........................................................ 9

8. Ventral hindwing much lighter gray than ventral forewing, hindwing discal spot darker than postmedial line (Figs 106–109)........................ L. perplexa

– Ventral hindwing and forewing similar color, hindwing discal spot and postmedial line similar in darkness (Figs 113–115)......................... L. subalpina

9. Orbicular spot filled with whitish scales, lighter than other spots and lines, irregular diamond, ovoid, or teardrop shaped (Figs 106–109) [character will not separate all specimens]......................................................... L. perplexa

– Orbicular spot round, slightly paler than ground color, similar to filling of lines, with a faint central ocellus (Figs 110–112) [character will not separate all specimens].......................................................................... L. perplexella

10. Male costal lobe of sacculus extending above costal margin of valve with broad flattened apex (Figs 183, 184); female corpus bursae without prominent constriction at base of appendix bursae (Figs 238, 239) AND hindwing yellow brown, not white; Forewing bluish gray, usually with warm yellow and reddish areas, AND hindwing yellow brown with gray marginal band, prominent dorsally and faint ventrally (Figs 101–105)............. L. impingens

– Costal lobe rounded, variable in size; corpus bursae with at least ¼× diameter constriction near ductus bursae, or if weakly constricted then hindwing ground white; appearance without above combination of characters........ 11

11. Digitus of male valve flat, triangular, tapering evenly from base to apex (Figs 163–168), or strap-like with bluntly pointed apex (Fig. 169); corpus bursae of female weakly constricted (̴ ¼× diameter) near ductus bursae (Figs 219–225); ventral and dorsal hindwing similar with pure white ground, dark basal suffusion, discal spot and sharply defined gray or black marginal band, and absent or very faint postmedial line (rarely prominent in heavily suffused specimens) (Figs 47–59) (L. staudingeri sub-group).................... 12

– Digitus of male cylindrical (or rarely, tapering to a cylindrical apex if base triangular); corpus bursae with at least 50 % posterior constriction; hindwing without above combination of characters, if pure white then dorsal and ventral patterns dissimilar OR postmedial line prominent even in pale specimens........................................................................................................ 18

12. Discal spot of dorsal hindwing large, ratio of width to height> 0.5 (Figs 54– 58); male antenna weakly bipectinate (total width <2× width of central shaft)....................................................................................................... 13

– Discal spot of dorsal hindwing normal, width to height <0.5; male antenna bipectinate (> 2× width of central shaft)................................................... 15

13. Forewing light yellowish gray with distinct lines and spots (Fig. 54); occurring in Colorado............................................................ L. q. quadrilunata

– Forewing slate gray with faint or absent lines; occurring north of Beartooth Plateau on Montana-Wyoming border..................................................... 14

14. Forewing with faint sinuous am line (Fig. 55–56); male digitus short and broad like an obtuse triangle and ending above valve margin.................................................................................................... L. quadrilunata yukona

– Forewing even slate gray, am line absent or straight if visible (Figs 57–58); digitus long, shaped like an acute triangle and extending below valve......... L. lagganata

15. Forewing medium gray to dark gray with well-defined markings (Figs 47–49, 52–53)..................................................................................................... 16

– Forewing otherwise, either light gray with indistinct lines and spots OR uniform dark gray without markings (Figs 50–51, 59).................................. 17

16. Forewing dark gray with patches of olive green; occurring in arctic (Figs 47–49)..................................................................... L. staudingeri

– Forewing pale gray, lacking olive; occurring in Colorado (Figs 52–53)............................................................................................................... L. dolosa

17. Forewing uniform slate gray, lacking all lines and spots (Fig. 59)................................................................................................................... L. carolynae

– Forewing light gray with discernible lines and spots (Figs 50–51)............................................................................................................... L. subfumosa

18. Ventral hindwing postmedial line closer to marginal band than discal spot, or postmedial line too faint to assess; usually small species with forewing expanse less than 30 mm (Figs 19–46, 60, 91, 93) (exceptions to size rule: L. sasquatch (Figs 40–42), L. benjamini (Figs 43–46), L. pulverea (Figs 91, 93)) (L. leucocycla sub-group; L. phoca sub-group (part))................................ 19

– Ventral hind wing postmedial line appearing closer to discal spot than marginal band; most species with expanse greater than 30 mm (exceptions to size rule: L. phoca (Figs 61, 62) and L. macleani (Fig. 94)).............................. 30

19. Eye reduced when viewed from anterior (2× eye width / distance between outer eyes <0.5)....................................................................................... 20

– Eye normal size (above ratio> 0.5)........................................................... 23

20. Forewing light gray checkered with dark gray along costa, in median area, and preceding subterminal line (Fig. 60); occurring in Sierra Nevada.................................................................................................................. L. mono

– Forewing more uniform, appearing mottled but not checkered; occurring elsewhere................................................................................................. 21

21. Dorsal hindwing dark gray (Figs 31–32); restricted to northern Yukon, northwestern Northwest Territories, and northern Alaska.......... L. coracina

– Dorsal hindwing white or yellow; more widely distributed, including in region described above................................................................................ 22

22. Male antenna bipectinate, total width> 2.1× central shaft; occurring in northern British Columbia, southern Yukon, and Alaska; ventral hindwing postmedial line complete (Figs 38, 39)........................................... L. illima

– Male antenna biserrate, <2.1× central shaft; widely distributed in northern North America and Rocky Mountains; if from range described above then ventral hindwing postmedial line absent or restricted to veins near costa (Figs 25–26)............................................................................ L. leucocycla

23. Ventral hind wing lacking postmedial line; color of entire moth brownish (L. pulverea (part) (Figs 90–93)..................................................................... 42

– Ventral hind wing with easily identified dark postmedial line; moth variably colored, including brown......................................................................... 24

24. Color of entire moth dark, nearly black (Fig. 33); occurring in boreal forest zone of northeastern and north central North America.......... L. anthracina

– Color of hindwing lighter with contrasting dark markings; occurring in Newfoundland, Labrador, or western North America............................... 25

25. Ventral hindwing brown or brownish gray (Figs 37, 40–46).................... 26

– Ventral hindwing off white with at most a brown or orange tint (Figs 30, 34–36)..................................................................................................... 28

26. Subterminal line strongly toothed basad in fold and preceded by a dark scales on veins producing a streaky appearance of distal forewing; ventral hindwing postmedial line with dark extensions along veins, appearing dentate (Figs 43–46)........................................................................... L. benjamini

– Subterminal line irregular and preceded by patchy darker shade but not as above, appearing mottled but not streaked; hindwing postmedial line dark and sinuous but not dentate..................................................................... 27

27. Ventral hindwing discal spot and postmedial line thick and darker than marginal band (Fig. 37); occurring from northern Wyoming to New Mexico................................................................................................. L. coloradensis

– Ventral hindwing discal spot, postmedial line, and marginal band similar dark gray (Figs 40–42); occurring in western Washington and Oregon........................................................................................................ L. sasquatch

28. Male antenna biserrate, total width <2.1× width of central shaft; hindwing off-white with orange brown tint (Fig. 30); occurring in Newfoundland and southern Labrador)........................................................................ L. flanda

– Male antenna bipectinate,> 2.1× central shaft; ground color of hindwing white or off-white with faint brown tint; occurring in Northwest............ 29

29. Dorsal hindwing white; ventral hindwing postmedial line thick and black, equal to discal spot and marginal band in intensity (Figs 35–36); widely distributed in northwestern North America including Alberta............... L. poca

– Dorsal hindwing pale brownish off-white; ventral hindwing postmedial line lighter than discal spot and marginal band (Fig. 34); restricted to western Alberta.......................................................................................... L. frigida

30. Ventral hindwing white to dark gray, without brown tint; dorsal forewing ground color gray (Figs 61–77, 79–81) (L. phoca sub-group (part))......... 31

– Ventral hindwing with yellow or brown tint; dorsal forewing brown, brownish gray, or olive brown (Figs 74, 78, 82–100) (L. promulsa sub-group; L. phoca sub-group (part))............................................................................ 39

31. Ventral hindwing with dark scales on veins between postmedial line and marginal band (Figs 63–69, 75)..................................................................... 32

– Ventral hindwing with veins of ground color between postmedial line and marginal band.......................................................................................... 36

32. Distal forewing with patches of white scales opposite cell and in fold; both sides of hindwing with extensive white areas and limited dark basal suffusion (Figs 63–64); occurring in subalpine areas in Wyoming and Colorado............................................................................................................. L. discolor

– Distal forewing without prominent white distal to postmedial line; hindwing gray or white with dark basal suffusion; occurring elsewhere............ 33

33. Male corona predominantly single; forewing gray, without patches of bluish scales; occurring in Canadian Rocky Mountains or California (Figs 75, 80) (L. uniformis ssp.)..................................................................................... 34

– Male corona with more than two rows of setae; forewing dark gray to black with patches of blue-gray scales (Figs 65–69); occurring in Pacific Northwest......................................................................................................... 35

34. Ventral hindwing white; forewing mottled gray with distinct lines and spots (Fig. 75); occurring in northern California.................... L. uniformis shasta

– Ventral hindwing light gray; forewing uniform gray with faint markings (Fig. 80); occurring in Rocky Mountains of Canada.................................................................................................................... L. u. uniformis (part)

35. Dorsal hindwing white or pale gray with distinctly darker gray marginal band (Figs 65–67); female ovipositor lobes large and rounded (Fig. 232).................................................................................................................... L. gelida

– Dorsal hindwing dark gray with light scales limited to anal angle (Figs 68– 69); female ovipositor lobes normal size and pointed when viewed from above (Fig. 231)............................................................................. L. caesia

36. Ventral hindwing postmedial line an indistinct black even arc touching discal spot; dorsal forewing dark gray (Figs 61–62); widely distributed in subarctic region from west coast of Hudson Bay eastward.............................. L. phoca

– Ventral hindwing postmedial line not touching discal spot, or sinuous in fold if barely touching spot; distributed west of Hudson Bay or on Gaspé Peninsula of Quebec (L. uniformis ssp.)............................................................. 37

37. Ventral hindwing marginal band homogeneous gray, darker than postmedial line, with well-defined proximal margin; forewing nearly uniform gray, occasionally with olive scales (Figs 79, 81); occurring in Canadian Rocky Mountains and southern Yukon................................. L. u. uniformis (part)