19. YPSOLOPHIDAE

1	Vertex with long, rough shaggy hair-scales, their tips dilated and/or furcate 2

-	Vertex with apressed or loose scales, their tips not dilated or furcate 6


2 (1)	Flagellum ringed greyish brown and dark brown, almost filiform, not thickened with scales *Ochsenheimeria vacculella*
	10.0-15.0mm. Late June to mid August. Forewing pale ochreous, mixed or almost wholly suffused dark greyish brown; three veins running from cell into termen. Hindwing with basal area hyaline, ranging from one-third to one-half. Antenna with scape slightly thickened with scales.
-	Flagellum unicolorous, not ringed, thickened to three-fifth with shaggy or recumbent scales 3
	Hindwing with basal area either not (or hardly) hyaline or distinctly hyaline.

3 (2)	Flagellum thickened with recumbent scales O. urella (part, male)
	9.0-13.0mm. July to September (in Britain). Forewing dark greyish brown, obscurely irrorate blackish brown, sometimes paler coloured; a few scattered, suberect, dark, pale-tipped scales; three veins running from cell into termen; underside terminal cilia unicolorous or nearly so. Hindwing in basal area hardly hyaline. See for female couplet 4.
-	Flagellum thickened with shaggy scales, longest in middle of flagellum 4
	Forewing with three or four veins running from cell into termen; underside terminal cilia unicolorous or dark, whitish basally.

4 (3)	Scales thickening flagellum less than three times width of flagellum. Forewing underside with cilia unicolorous or nearly so O. urella (part, female)
	11.0-14.0mm. July to September (in Britain). Forewing sometimes coloured and marked as in male, but usually pale ochreous, or intermediate; obscure dark irroration and a few suberect scales; underside terminal cilia unicolorous or nearly so. Hindwing in basal area hardly hyaline. See for male couplet 3.
-	Scales thickening flagellum more than three times width of flagellum. Forewing underside with terminal cilia dark, whitish basally 5


5 (4)	Hindwing without hyaline basal area or at most to one-third O. taurella (part)
	10.0-13.0mm. July and August. Forewing ochreous or greyish yellow; clouded grey, sometimes tending to form fasciae; some loosely attached suberect scales in disc. This is f. mediopectinellus, until recently considered a separate species.
-	Hindwing hyaline from two-fifth to more than one-half O. taurella (part)
	11.0-16.0mm. July to early September. Forewing greyish brown; clouded blackish grey, often forming ill-defined fasciae.

6 (1)	Forewing with termen strongly concave, apex falcate 7

-	Forewing with termen not or weakly concave, apex or only very slightly falcate 11


7 (6)	Forewing deep brown with pale yellow, dorsal streak from base to tornus *Ypsolopha dentella*
	17.0-22.0mm. Late June to early September. Terminal cilia forewing with dark cilia-line. Frons brown, vertex and thorax white, tegulae brown.
-	Forewing not brown with pale dorsal streak 8


8 (7)	Larger species, 26.0-33.0mm *Y. mucronella*
	March, April. In Britain from August to April, adult hibernates. Forewing pale ochreous, with scattered blackish scales; a greyish brown streak along fold from base to beyond middle; a raised dark dot before middle. Frons, vertex, thorax and tegulae pale ochreous grey.
-	Smaller species, 15.0-25.0mm 9


9 (8)	Forewing straw yellow, without tufts of raised scales *Y. nemorella*
	21.0-25.0mm. Late June to mid August. Forewing pale ochreous, variably suffused brownish between veins, with scattered blackish scales; brownish grey streak along fold and blackish brown dot below fold before middle. Frons, vertex and thorax pale ochreous, tegulae ochreous.
-	Forewing with at least dorsal half dark greyish brown; with tufts of raised blackish scales 10


10 (9)	Forewing with costal half greyish white, veins lined brown; dorsal half blackish brown, somewhat purplish *Y. scabrella*
	16.0-23.0mm. Early June to early September. Forewing with black streak along fold and another along dorsum; three blackish scale-tufts below fold and one above tornus. Frons whitish, vertex greyish white mixed dark brown. Thorax greyish white.
-	Forewing wholly dark greyish brown, somewhat tinged purplish *Y. horridella*
	16.0-21.5mm. Late June to early September. Forewing with row of three black scale-tufts. Frons whitish, vertex dark greyish brown. Thorax dark purplish brown.

11 (6)	Forewing white with faint ochreous tinge and sharply contrasting blackish markings *Y. sequella*
	17.0-20.0mm. Late June to mid August. Forewing with three dark dorsal spots, more or less confluent and two smaller tornal spots, moreover dark streaks, fasciae and additional spots, often interconnected. Frons white, vertex and thorax white or whitish.
-	Forewing from pale ochreous to blackish; dark markings not sharply contrasting 12


12 (11)	Forewing with outer edge of cilia convex; ochreous yellow with dark transverse streaks, a more or less complete fascia or occasionally without markings 13
	Forewing sometimes with dark markings reduced to suffusions from dorsum before middle and from tornus.
-	Forewing with outer edge of cilia concave, sometimes only slightly; ochreous brown to blackish with longitudinal dark or pale markings, often without markings 15
	In some specimens forewing paler coloured, occasionally also dark transverse streaks.

13 (12)	Vertex and thorax yellowish white, tegulae ochreous. Forewing without distinct dark fasciae or streaks, at most suffusions from dorsum before middle and from tornus *Y. lucella*
	16.0-20.0mm. Late June to early September. Forewing pale ochreous, finely and indistinctly reticulated darker. Frons whitish.
-	Vertex, thorax and tegulae pale ochreous. Forewing with two oblique brownish fasciae, often not reaching costa 14


14 (13)	Forewing with incomplete fasciae, not extending half-way costa *Y. alpella*
	13.0-17.0mm. Late June to early October. Forewing whitish ochreous, indistinctly reticulated darker. Frons white; vertex, thorax and tegulae ochreous.
-	Forewing with two parallel fasciae extending more than half-way costa *Y. sylvella*
	17.0-20.0mm. Mid June to early October. Forewing brownish ochreous with darker strigulae. Frons white; vertex, thorax and tegulae ochreous.

15 (12)	Forewing with longitudinal markings or at least a dark spot above tornus 16
	Forewing with longitudinal markings sometimes restricted to dark dorsal streak.
-	Forewing unicolorous blackish or brown, or nearly so 18


16 (15)	Forewing greyish with irregular blackish streak along dorsum, occasionally interrupted; sometimes dorsal two-thirds of wing blackish Y. vittella (part)
	16.0-22.0mm. Early June to early September. Forewing ranging from pale grey to blackish. Frons and vertex greyish brown. Colour thorax variable, usually dark grey with pale longitudinal stripes or unicolorous dark grey; tegulae coloured as forewing. See couplet 18.
-	Forewing without or, occasionally with regular dark streak along dorsum 17


17 (16)	Vertex whitish or ochreous, usually paler than dark ground colour forewing. Forewing with ground colour from brown to ochreous and white. Hindwing underside greyish white *Y. parenthesella*
	15.0-19.0mm. Late May to early October. Forewing with white streak extending along basal half of costa, sometimes to apex; dark longitudinal streak along fold; occasionally white with dark longitudinal streak or unicolorous brown. Frons ochreous white. Thorax variable, from whitish to dark brown; tegulae from ochreous to dark purplish brown.
-	Vertex concolorous with ground colour of forewing. Forewing with ground colour variable, ranging from white to blackish brown. Hindwing underside dark grey *Y. ustella*
	15.0-20.0mm. Throughout the year except January; adult hibernates. Forewing with colour and markings extremely variable; usually dark spot above tornus; occasionally unicolorous. Frons, thorax and tegulae variable, usually coloured as forewing.

18 (15)	Labial palpus with terminal segment almost two times length scale-tuft second segment Y. vittella (part)
	Forewing blackish. See couplet 16.
-	Labial palpus with terminal segment and scale-tuft of second segment of equal length 17
	Forewing from pale ochreous to blackish brown.