Dicranota Zetterstedt, 1838: 851
Key to the Western Species of Dicranota (Rhiphidolabis)
- General coloration of body brown or gray; male hypopygium not as above...2
hypopygium with posterior margin of tergite including broad obtuse lateral lobes and slender
intermediate lobules that are separated by a broad U-shaped emargination (Fig. 2); venation (Fig. 3)......
...polymeroides (Alexander, 1914). USA (Alaska, Wash, Idaho, south to Calif).
- Antennae of male short, not extending to the wing root; male hypopygium with tergite not as above...3
3. Wings with Sc short, Sc1 ending opposite or before fork of Rs (e.g., Fig. 4)...4
- Wings with Sc longer, Sc1 ending some distance beyond fork of Rs, usually opposite or beyond the fork of
4. Wings with r-m ending before the fork of Rs, the latter very strongly arcuated, R2+3+4 short, suberect
(Fig. 4)...tehama Alexander, 1950. USA (Calif).
- Wings with r-m at or beyond fork of Rs, the latter relatively long, angulated and in cases short-spurred
beyond origin (e.g., Fig. 5)...5
median region of posterior border with a small circular emargination behind which is a darkened area
that bears numerous setae; basistyle without a modified arm on mesal face near apex (Fig. 6).............
...fenderi Alexander, 1954. USA (Oreg).
- Wings with cell R3 sessile; male hypopygium with posterior border of tergite broadly emarginate, the
sides with pale strong arms (e.g., Fig. 7); basistyle on mesal face near apex with a short to longer pale
arm that terminates in a blackened spine or elongate blackened blade, or else in a microscopic pale point
(Fig. 8)...nooksackensis group, 6
...nooksackensis Alexander, 1949. Canada, USA (Alaska, south to Oreg and Calif).
- Apical arm of basistyle longer, the pale base subequal to or longer than darkened outer part...7
7. Apical arm of basistyle stout, terminating in a microscopic pale point (Fig. 8E)....................................
...brevicula Alexander, 1966. USA (Calif).
- Apical arm of basistyle terminating in a blackened blade or spot (Fig. 8B-D)...8
8. Apical arm of basistyle long and slender, terminating in a short blackened spinelike point that is
extended farther into a paler setoid prolongation (Fig. 8B)...brevispinosa Alexander, 1958. USA (Wash).
- Apical arm of basistyle shorter, terminating in a blackened blade, the apex obtuse...9
9. Apical arm of basistyle with the blackened apex longer, only slightly less than the pale basal stem
(Fig 8C)...denningi Alexander, 1966. USA (Calif).
- Apical arm of basistyle with the blackened apex relatively short, slightly more than one-half the pale
basal stem (Fig. 8D)...evanescens Alexander, 1966. USA (Calif).
10. Wings with cell R3 sessile or subsessile, in the latter case (subsessilis) with R2+3+4 shorter than basal
section of Rs, the latter equal to r-m (Figs. 9, 10)...11, sessilis (Alexander, 1917), USA (Colo), known
from a single female, keys here.
- Wings with cell R3 petiolate (Fig. 5)...16
- Male hypopygium (Figs. 12-14) with median region of posterior border of tergite slightly produced or
truncate, not emarginate...13
present, nearly as long as r-m; male hypopygium with the median emargination broad, the lobes
divergent (Fig. 7)...uniplagia Alexander, 1954. USA (Oreg). While the wing was not drawn or described,
the large body size and structure of the male hypopygium (Fig. 19), would place stigma
(Alexander, 1924). USA (Wash, south to Colo), near this species. This may be incorrect if R3 is not
- Size smaller (wing of 8 about 8 mm); wings without a darkened cloud over r-m; basal section of vein
Rs obliterated, r-m at the fork of R4+5; male hypopygium (Fig. 11) with the median emargination
the lobes less divergent...sanctaeluciae Alexander, 1964. USA (Calif).
13. Male hypopygium with median region of posterior border of tergite and mesal face of basistyle
with unusually long setae (Fig. 12)...trichopyga Alexander, 1966. USA (Calif).
- Male hypopygium (figs. 311,313) without unusually long setae on the tergite or basistyle
(Figs, 14, 15)...14
14. Wings milky white, without stigmal darkening, veins pale (Fig. 10); male hypopygium with interbase
a long swordlike blade; tergite without lateral arms (Figure 13).......................................................
...subsessilis (Alexander, 1921). Canada, USA (BC to Mont and Wyo, south to Calif).
- Wings with stigmal darkening more evident, veins darker; male hypopygium with interbase short,
tip bispinous; lateral tergal arm present, their tips obtuse (Fig. 14)...15
15. Wings with stigma faint to scarcely &dent, in cases pale brown.......................................................
...cayuga (Alexander, 1916). Canada, USA (Alaska to Nfld, south to Oreg, Colo and SC).
- Wings with stigma conspicuous, brown to dark brown (Fig. 9); male hypopygium (Fig. 14)..............
...vanduzeei (Alexander, 1930). USA (Calif).
16. Wings faintly suffused with brown, the stigma barely evident; R2+3+4 subequal to r-m (Fig. 5).....
...nuptialis Alexander, 1948. USA (Calif).
- Wings more whitened, stigma usually conspicuous; R2+3+4 slightly longer than r-m...17
17. Male hypopygium (Fig. 15) with basistyle produced into a single apical lobe, on its face with a slender
lobule tipped with blackened spinoid setae; tergite with median region of posterior border produced
into a conspicuous lobe that is weakly dilated a t outer end, the posterior border virtually truncate or
very feebly emarginate...integriloba Alexander, 1943. USA (Wash and Idaho, south to Calif and Colo).
- Male hypopygium (Figs. 16-18) with basistyle produced into two separated apical lobes;
tergite with median region only slightly produced, the extreme in querula where the lobe is relatively
short, the sides parallel...26
a parallel-sided lobe; apex of dististyle narrowed into a slender lobe (Fig. 16)........................................
...querula Alexander, 1944. USA (Oreg, Idaho, Utah and Calif).
- Wings with stigmal darkening conspicuous; male hypopygium with median region of tergite convexly
rounded; dististyle not narrowed at apex...19
19. Male hypopygium with lateral tergal lobes short and broad, the apical point short (Fig. 17)..................
...neomexicana (Alexander, 1912). Canada, USA (Alaska, south to Calif, Ariz, NMex and Colo). A former
subspecies, subtruncata Alexander, 1949. USA (Wash), would key here. This species isn't illustrated but
Alexander's description states "the ninth tergite virtually truncate, the margin at this point very slightly
convex and with a concentration of setae. Two or three setae at the apex of the dististyle long and
conspicuous." It should otherwise conform to D. neomexicana (Fig. 308).
- Male hypopygium with lateral tergal lobes relatively narrow, extended into a long terminal spine
(Fig. 18)...cazieriana Alexander, 1944. USA (Oreg, Calif and Utah).
An additional species, Dicranota major (Alexander, 1917), is known only from a single female (USA: Colo) and isn't able to be placed in the key. This is a very large taxon, the largest in the genus according to Alexander (1917). There are no illustrations but crossvein r is removed from R1.
Dicranota (Rhaphidolabis) avis (Alexander, 1926). USA (Maine, south to NC).
Dicranota (Rhaphidolabis) forceps (Alexander, 1924). Canada, USA (Mich to NSc, south to Tenn).
Dicranota (Rhaphidolabis) hickmanae Alexander, 1940. USA (Tenn).
Dicranota (Rhaphidolabis) persimilis (Alexander, 1920). USA (Pa and Md, south to Tenn and SC).
Dicranota (Rhaphidolabis) rogersiana (Alexander, 1925). Canada, USA (Mich, Que).
Dicranota (Rhaphidolabis) rubescens (Alexander, 1916). Canada, USA (Que to NSc, south to NY and Mass).
Dicranota (Rhaphidolabis) tenuipes (Osten Sacken, 1869). Canada, USA (Mich to NBr, south to Md and Va).