A. L. Melander.
The Genus Cyrtopogon (Diptera; Asilidæ).
Psyche 30:102-119, 1923.

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102 Psyche June-August
In the elaboration of Osten Sacken1s table of Cyrtopogon given in Back's 1909 study of Robber-flies thirty species are included. This genus is particularly well represented in the Pacific States and several new forms have been discovered by western collectors since the publication of Back's review. Ac- cordingly the following indentification table is appropriate to bring to date our knowledge of this group of especially in- teresting flies. References are given in the table to those species described since Back's paper was published. Many of the species of Cyrtopogon exhibit sex dimorphism. This is particularly the case with those species having red an- tennse.
At times the males and females look quite unlike. The males present easy recognition characters in their elaborate and brilliant sex attire, but sometimes the more modest appearing females of several species resemble each other so closely as to be differentiated with difficulty.
The characters used in the table are for themost part reason- ably constant. There is some individual variation in the color of the legs and of the hairs of face, hypopleurae, scutellum, ab- domen and legs, and in the extent of interruption of the ab- dominal fasciae. Where such variations have been sufficient to cause doubt in interpreting the table, cross-references have been introduced for more accurate guidance. Types of the new
species are in the writer's collection.
Key to the Species of Cyrtopogon.
1.
Scutellum convex, generally long-pilose, usually shining or with touch of pollen at base, rarely pollinose among the species with long arista. . . . . . . . . . . . . 2. Scutellum flattened and uniformly and quite densely pol- linose; antennae black. . . . . . . . . . . . . . . 32. IContributionfrom the Zoology Laboratory of the State College of Washington.



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19231 The Genus Cyrtopogon 103
2.
Third antennal joint red; mystax largely white or yellow;. (if halteres are blackish and face has white hairs, see longimanus; if large species with base of abdomen densely pilose, see dasyllis) . . . . . . . . . . . . . . . 3 . . . . . . . . . . . . .
Third antenna1 joint black.
11 .
. . . . . . . . 3. Tibiae and tarsi more or less reddish. 4. Legs black; claws white with black tip. . . . . . . . 10. 4.
Pile of scutellum and hypopleurae white; apex of femora reddish; mystax mostly white; pile of tibise and pleurae very long. (Can., N. H., Ct., N. Y., Mass., Va., N. C. marginalis Lw.
Pile of scutellum black; of hypopleurse more or less black; femora black; western species. . . . . . . . . . . 5. 5.
Front tibiae and tarsi of male silvery pilose on posterior . . . . . . . . . . . . . . .
side; wings hyaline. 6.
Legs not silvery, but sometimes with yellowish white hairs fringing tarsi; pile of male abdomen more or less tufted; wings with light clouding about veins, anterior crossvein . . . . . . . . . . . . . .
near base of discal cell. 7.
6.
Male: front tibiae with fine white silky pile on outer side, becoming longer and denser apically; front tarsi with. silvery hairs on anterior side of joints 2-5 in addition to the silvery hairs on posterior side; abdominal segments 1,2 with pale yellow pile,longer on sides,remaining segments with very short hair, yellowish on 3, black on rest, segments 2-5 white-fasciat'e, interrupted on 4,5. (Col.) pulcher Back
Male: front tibiae with moderately long silvery pile pos- teriorly, short yellow pile anteriorly; front tarsi with yellow hairs on anterior side of first two joints; abdomen with reddish yellow pile forming dense apical bands on segments 1-4, segments 2-4 silvery fasciate. (Alta.) . . . . . .
(Can. Ent. liv. 278, 1922)
albitarsii Curran.
7.
Pile of abdomen yellow or fulvous at least on first segment, tip of male abdomen blue-black, segments 2-4 with com- plete fascise, sometimes hidden by dense pile in male; . . . . . . . . . . . .
basal half of claws reddish.
8.




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Psyche [June-August
Male abdomen with lateral tufts of black not fulvous hair, female with less tufted black and white pile, ab- domen with interrupted white pollinose fasciae; claws black, front tarsi of male very long. (Or.) (Proc.Ca1. Acad. Sc., 1919, 233) . . . . . . . . . . .perspicax Cole 8.
Male abdomen with black tuft on sides of second segment, a dorsal pollinose vitta on segments 2-5, female abdomen with lateral pile pale yellow and almost entirely confined to basal two segments; male front tibiae with white pubescence toward tip, tarsi yellow with brush of yellow- ish-white hairs along entire outer face and with black bristles inside, tarsi of female reddish; central hairs of face mixed black and white. (Wash.) . . glarealis, n. sp. Male abdomen with dense fulvous pile arranged in tufted bands across segments 2-4, no dorsal vitta, yellow pile . . . of female abdomen continuing on third segment. 9.
9.
Segments 5-7 of male abdomen with dense tufts of short black velvet pile; front tibiae and tarsi without brush on posterior side, bristles black, some white pile on extensor face of male tarsus; female with tarsal joints tipped with black and with center hairs of face white. (Cal., Wash.) . . . . . . . . . . . . . . . . . aurifex 0. S. Segments 5-7 of male abdomen not tufted; posterior edge of front tibiae and tarsi of male with uniform brush of white hairs containing white bristles; female with yellowish tarsi and with central hairs of face yellow. (Or., Id.) (Proc. Gal. Acad. Sc. 1919, 230.) . . . . . auratus Cole 10. Thorax white-gray pollinose, markings nearly obsolete; wings hyaline; face and front heavily coated with cinere- . . . . . ous pollen. Male unknown. (Cal.) cretaceus 0. S. Thorax of male black, of female brown and gray; wings of male black, of female subfuscous; male front tarsi very long, silvery on extensor side, hind tibiae and tarsi silvery pilose. . . . . . . . . . .
(Gal., Or., Wash.)
princeps 0. S.
11.
Style nearly as long as third joint of antennae; wings with distinct dark spots on furcations and crossveins; scutel- lum often dusted. . . . . . . . . . . . 12.



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19231 The Genus Cyrtopogon 105
. .
Style evidently shorter than third joint of antennae. 15.
Thorax compressed gibbous, the undivided median stripe bearing a strong mane of long black pile and setiform hairs; scutellum margined with long black setee; costal and marginal cells hyaline; halteres black. (Wash.) . . . . . . . . . . . m~aculosis coq.
Thorax convex as usual, with erect black pile but no mane; scutellar bristles less developed; middle dorsal stripe . . . . . . . . . . . . . . . . . . .
geminate. 13.
Costa fringed with uniform close hairs; pile of face tipped. with white; halteres black. (Cal., Or., Wash., B. C.) nebulo 0. S.
Costa with only microscopic hair; white tips of facial hairs less evident; costal and marginal cells brown apically. 14. Halteres black; a single spot in first basal cell at origin of . . . . . .
third vein. (Id., Wash.) punctipennis, n. sp. Halteres yellowish; first basal cell with two blackish spots near middle. (Wash., Or.) . . . . . varipennis Coq. Abdomen with dense erect pile forming a bright yellow band across middle part, and black at tip. . . . . . . . . 16, Abdomen not densely clothed but sometimes with lateral or parted tufts of pile in male. . . . . . . . . . . . 18. Style short and thick, almost square; wings hyaline; an- terior crossvein near base of discal cell; anterior tibise and front tarsi with dense white pile on extensor face; yellow pile of abdomen confined to basal three segments. (Wash.) . . . . . . . . . . . . . . sernitarius. n. sp. Style longer than wide; anterior crossvein near middle of discal cell; hairs of legs black aside from the fulvous re- cumbent pubescence on inside of front tibiae. . . . . 17. Wings of male with large black sharply limited spot; all hairs of head black; yellow hairs of abdomen confined to segments 2-4 (Col., Id.) . . . . . . . . . dasyllis Will. Wings with dark spot more suffused; hairs of face and beard yellow; yellow hairs of abdomen extending on fifth seg- . .
ment. (Wash., Or., Id., Cal., N. Y.) .dasylloides Will.



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106 Piyche [June-August
18.
At least hind tibiae in part reddish, usually anterior pairs also more or less reddish. . . . . . . . . . . . . 19. Legs entirely black, sometimes hind tibiae with dark cas- taneous tinge. . . . . . . . . . . . . . . . . . 27. 19. Wings of male with two large black marks; vertex little excavated and heavily deep golden pollinose; mesonotum deep golden pollinose, the four corners shining; mystax golden; abdomen with yellow lateral tufts; segments 2-5 with broadly interrupted posterior fasciae. Wings of female infuscated over apical part and over end of anal cell; color of pile and pollen less deep. Anterior crossvein near middle of discal cell. (N. H., Minn., N. M., Col., Wyo., Id., Or., Wash.) . . . . . . . bimacula Walk. Wings not bimaculate; vertex more evidently excavated; 20. 20. Abodmen of male with a large tergal patch of dense fulvous tomentum; hypopleural hairs white. (Ont.) vulneratus,n. sp. . Abdomen without such mark of fulvous tomentum. . 21. 21. Male front tarsi with recumbent silvery pile, last two ,joints of middle tarsi of male with disk of black hairs; gray pruinose marks of abdomen very small and located at hind angles of the segments. (If male front tarsi silvery but middle tarsi without disk, see tacomce.) . . . . . . 22. Front tarsi without silvery recumbent hairs and middle tarsi without black disk. . . . . . . . . . . . . . 25. 22.
Silvery hairs of male front tarsi parted; black disk of middle tarsi confined to last two joints. . . . . . . . . . . 23. Silvery hairs of front tarsi not parted, beginning on second joint; short black hairs on third joint of middle tarsi be- ginning the disk; pulvilli dark brown. . . . . . . . 24. 23.
First two segments of abdomen with whit,e pile on sides, in male contrasting with black pile on remainder; front metatarsi of male not silvery above, but densely beset on both sides below with black bristles; pulvilli whitish. (Cal., N. M., Wyo., Col.) . . . . . . callipedilus Lw. Abdomen with black pile over all; front metatarsi of male silvery above and not spinose beneath; pulvilli brown. (Cal.) . . . . . . . . . . . . . . cymballista 0. S.



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19231 The Genus Cyrtopogon 107
24.
Scutellum and most of thorax shining; pile of abdomen yellow and black. (B. C. ,Alta., Wash.) (Can. Ent. 1922, 277) . . . . . . . . . . . . . . . willistoni Curran. Base of scutellum and much of thorax brown pollinose; pile of abdomen yellow.
(N. M., Utah, Id., Col., Neb.)
plausor 0. S.
. . . . . . . . . . . . .
25. Gray pruinose marks of abdomen confined to hind angles of segments; pile of face deep golden; pile of hypo- pleurae yellow, of abdomen yellow except at end; tibiae abruptly black on apical half. (N. S., Queb., Ont., N. H., Mass., N. Y., Ct., N. J., N. C., Fla., 111.) (If legs are entirely dark chestnut, see alleni) . . . . falto Walk. Gray pruinose marks following hind margins of abdominal segments; pile of face whitish, black on sides; hind tibiae not black apically. . . . . . . . . . . . . . . . 26. 26. Hairs of hypopleurae black; abdominal fasciae narrowly interrupted, sometimes entire in female; pile of abdomen mainly black. (Col., N. M., Cal., Id., Wash., B. C.) montanus Lw.
. . . . . . . . . . . . . . . . . . .
Hairs of hypopleurse white; abdominal fasciae entire; pile of abdomen white Male unknown. (Cal., N. M., Or.) leucozona Lw.
. . . . . . . . . . . . . . . . . . .
27.
Middle segments of abdomen with complete fasciae; male front tarsi elongate, tarsal hairs chiefly white, long on upper side of basal three joint's of hind pair, tarsal hairs of female chiefly black; hypopleural hairs black; halteres blackish brown; extensor hairs of hind tibiae white. (Cal., Wash., B. C.) (If hind tibiae are dark chestnut color, see montanus) . . . . . . . . . . . longimanus Lw. Fasciae of abdomen interrupted, sometimes reduced to . . . .
lateral spots; crossveins, etc., usually clouded. 28.
28.
Fasciae broader than long, following the hind margins; . . . . . . . . . . . .
front tarsi of male slender,
29.
. . . . .
Fasciae confined to hind angles of segments. 30.
29.
Front tibiae and tarsi of male with not dense white pilef which does not conceal the ground-color; hind tarsi o,



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Psyche [June-~u~ust
male darker than others; claws broadly yellowish; humeri subshining. (Mont.) . . . . . . . . . rufotarsus Back. Front tibiae and tarsi of male with appressed silvery pile concealing the ground-color at least of tarsus; middle tarsi darkest; claws black the base reddish; humeri and adjacent region of thorax heavily silvery-white pruinose. (Wash.) . . . . . . . . . . . . . . . tacom~ n. sp. 30.
Front tarsi of male with single row of silvery pile from very base; last two joints of middle tarsi with the flat disk of black pile longer than broad; pile of abdomen yellowish white at base, black apically. (Wash., Or.) (If front metatarsi of male are not silvery, see Willistoni) . . . . . . . . . . . . . . . . . . . . prcepes Will. Front and middle tarsi of male not ornamented. . . . 31. 31.
Scutellum with long black pile; mystax and hypopleurae pile black; pleurae shining above; notal pattern including mark like a tuning-fork. (N. H., N. Y ., N. C.) lyratus 0 .S. Scutellum with short white pile; mystax partly white, hypopleural pile white; pleurae densely white pruinose. (N. H., N. C.) . . . . . . . . . . . . . dleni Back. 32.
Abdomen with pollinose markings at least of segments 2- . . . . . . . . . . .
4 extending from side to side.
33.
Abdominal fasciae interrupted, sometimes subinterrupted,, . . . . . . .
that of first segment sometimes entire.
39.
33.
Greater part of middle segments of abdomen covered with gray pollen and the front angles polished; hypopleural . . . . . . . . . . . . . . . . . . .
pile white. 34.
Greater part of abdominal segments shining, or if largely pollinose the pollen extending along the sides so that the front angles are not polished. . . . . . . . . . . . 36. 34.
Pollen denuded in circular spot in middle of each tergite; tibiae with many white bristles, male with brushes of white hair on front side of middle tibiae below knee and on front side of middle metatarsi. (Wash.) . . . ablautoides, n. sp. Middle of tergites pollinose, or if shining not forming a central round spot; white hairs of legs evenly distri-
. . . . . . . . . . . . . . . . . . . . . buted. 35.




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19231 The Genus Cyrtopogon 109
35. Hypopleural pile black; hairs of hypopygium yellowish white; mystax white; abdomen of both sexes gray except front angles of segments; tibial bristles white except those at tips and on front side of first pair. (Cal.) . . rattus 0. S.
Hypopleural pile white; hypopygial hairs black above; mystax white and black; anterior half of male abdominal segments shining; tibial bristles black, a few pale ones on extensor side of hind tibiae of female. (Wash.)
ccesius, n. sp.
. . . . . . . . . . . . . . . . . . .
36.
Face convex below but not gibbous, facial pile dense and white; tibiae reddish at base; male abdomen broad, with sides and posterior margins pollinose, female abdomen narrow, anterior margins of segments 2-4 sometimes also pollinose. (Or., Wash.) (Proc. Cal. Acad. Sc. 1919, 230) . . . . . . . . . . . . . . . . anomalus Cole. . .
Face more gibbous, its pile largely or wholly black. 37,
37.
Legs largely brownish red; geminate stripe of thorax dis- tinct and complete; pollen of abdomen confined to pos- terior and side margins of segments; style one-third the third antennal joint ; scutellum without bristles ; face and front brownish gray. (Ks., Col., N. M.) . . profusus 0. S. Legs black; scutellum with black bristles. (If scutellum
with only marginal pile, see nugator female if facial hairs all black, or ccesius male if facial hairs white.) . . 38. 38.
Abdominal fasciae extending along posterior edge of seg- ments; stripes of thorax very distinct. (Cal.) evidens 0. S. Abdominal fasciae extending along anterior margin of seg- ments 2-6 but not reaching sides,posterior angles with spots of white pollen; stripes 6f thorax indistinct; style one-tenth the third antennal joint. (Cal.) cerussatus 0. S. 39. Legs in part reddish; mystax black, . . . . . . . . . 40. Legs black, rarely the knees alone brownish. . . . . . 41. 40. Hypopleural pile whitish; mystax rather sparse; wings hyaline; mesonotum largely gray. (Ariz.) . tibialis . Coq. Hypopleural pile black; mystax dense; wings brownish apically, crossveins clouded; mesonotum largely brown. (Or.) ................. dubius Will.
.




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110 Psyche [~une-August
41.
Bases and hind angles of abdominal segments pruinose, sides of first segment pruinose; ant,erior crossvein beyond middle of discal cell; mystax and hypopleural hairs main- ly black; thorax largely gray, marks diffuse, pleura bear of pile, scutellar margin with strong bristles. (Cal.) . . . . . . . . . . . . . . . . nigricolor Coq. No fasciae at base of segments; scutellum more or less pilose; thorax darker. . . . . . . . . . . . . . . . . . 42. . . . .
42. Hypopleural pile wholly or in large part white. 43. . . . . . . . . . . . Hypopleural pile wholly black. 47. 43. Pleurae with polished spot beneath wings; tibial bristles white; first abdominal segment with entire fascia. (N.
S., Mass.. N. Y. Md. Va.) . . . . . . lutatius Walk. Pleurae wholly pollinose and with some fine pile; tibial bristles mainly or entirely black; fascia of first segment of abdomen interrupted. . . . . . . . . . . . . . . 44. 44.
Scutellar pile pale yellow, wings hyaline; facial pile mixed white and black. (Or.) (Proc. Cal. Acad. So. 1921, 255) thompsoni Cole
. . . . . . . . . . . . . . .
Scutellar pile black. 45.
45. Scutellar pile abundant; wings dark, especially in male; facial pile white in male, black in female. (Or.) (Proc. Cal. Acad. Sc. 1919, 233) . . . . . . . . infuseatus Cole. . .
Scutellar pile sparse and marginal; facial pile black. 46.
46.
Tarsal claws yellowish with black tip; wings hyaline; median st-ripes as distinct as the blackish lateral spot. (Cal.,
Or., Wash., Id.) . . . . . . . . . . nugator 0. S. Tarsal claws reddish at base, otherwise black; wings brown- ish hyaline ; median geminate stripe of mesonotum abbrevi- ated posteriorly and less distinct than the rich dark brown lateral spot. (Cal. Or.) . . . . rejectus 0. S. 47.
Front and face broad, cinereous; notal marks often feeble. (Gal., Or., Wash.)
. . . . . . . . . . . . sudator 0. S.
Front and face relatively narrow, brownish; notal stripes coalescing, dark brown. (Cal., Ariz., N. M., Id.) positivus O.S.




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The Genus Cyrtopogon
Ill
Cyrtopogon ablautoides, new species
Male.-Length 11 mm.
Head cinereous pollinose, frontal
hairs whitish, becoming black at orbits, hair of center of face dense and white with slight yellowish tinge, of sides and beneath black, hairs of occiput abundant, silvery, nearly white, antennae slender, the
style one-fourth as long as third joint, its basal segment scarcely visible.
Thorax dusted with yellowish-gray
pollen, the geminate stripe interrupted one-third the distance in front of scutellum, lateral stripes nearly obsolete, slightly darkened in front of suture and a weaker indication behind, three strong lateral presutural bristles, four intraalar, post- alar callosities with four black bristles; hairs of notum white in front, a few blackish hairs intermixed behind, scutellum flat, brownish-gray pollinose, disc with erect white pile, margin with white pile, about six black setae, pleurae gray pollinose with yellow- ish tinge on mesopleura which also bears long white pile, tri- chostical hairs yellowish-white. Abdomen with shining or subshining anterior margins to the segments the posterior margins white pruinose, a central subshining black spot on each of segments two, three and four, sides of segments two, three and four subshining except posteriorly, the first three segments bearing dense lateral tufts of whitish yellow hair, hair of re- maining segments sparse short and white, hypopygium small and subshining black. Legs dusted, femora with whitish pile,