Calyxochaetus cilifemoratus
Creators: name: Runyon, Justin B.
Publisher: name: Zenodo
Year: 2024
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Diptera
Dolichopodidae
Calyxochaetus
Calyxochaetus cilifemoratus

description: Calyxochaetus cilifemoratus (Van Duzee)
(Figs 29, 42, 59, 72)
Nothosympycnus cilifemoratus Van Duzee, 1924: 12.
Calyxochaetus cilifemoratus: Parent (1930: 107).
Sympycnus fuscitibialis Harmston & Knowlton, 1940: 400; synonymized by Harmston (1947: 98).
Type material examined. Nothosympycnus cilifemoratus: HOLOTYPE ♂, labeled: “Anchorage Alsk/ VI-11-21”; “ Nothosympycnus / cilifemoratus / Holotype. Van Duzee” (USNM). PARATYPES: USA: Alaska: Same data as holotype, 15.vi.1921, J.M. Aldrich (2♂, USNM).
Sympycnus fuscitibialis: HOLOTYPE ♂, labeled: “ Currant Creek / UT. June 29, 1939 ”; “ G.F. Knowlton / F.C. Harmston ”; “Type No/ 54300/ U.S.N.M.”; “ HoloType / Sympycnus / fuscitibialis / n.sp. F.C.H.-G.F.K.”; “ Sympycnus / fuscitibialis H&K/ Det. 1940 F.C. Harmston ” (USNM). PARATYPE: USA: Utah: Same data as holotype (1♂, LACM).
Other material examined. CANADA: Alberta: Lesser Slave Lake, 21.vi.1952 (1♂, CAS). Northwest Territories: Norman Wells, 2.vii.1969, G.E. Shewell (4♂, CNC). USA: Alaska: Matanuska-Susitna Borough: Knik Lake, SW of Wasilla, 18.vii.1978, sweeping vegetation edge of lake, P.H. Arnaud, Jr (1♂, CAS). Colorado: Boulder County: Ward, 25.vi.1962, FCH (2♂, FSCA); 3 mi N of Nederland, marshy stream margin, 8500 ft, 2.vii.1961, J.G. Chillcott (3♂, CNC); Nederland, seepage area, 8300 ft, 5.vii.1961, J.G. Chillcott (1♂, CNC); Eagle County: Tennessee Pass, 21.vii.1966, FCH (2♂, CAS); same data except, 24.vii.1917, J.M. Aldrich (1♂, USNM); same data except, 16.vii. 1930, 10240 ft (1♂, USNM); Gunnison County: Crested Butte, 8.viii.1968, FCH (1♂, FSCA); Park County: Platte Canyon, near Idlewild, 10.vi.1927, J.M. Aldrich (1♂, USNM); San Juan County: Molas Divide, 11.vii.1962, FCH (1♂, CAS); Summit County: Loveland Pass, 12.viii.1958 (1♂, CAS). Montana: Glacier County: 1.6 mi W of Babb, 4675 ft, 10.viii.2002, JBR (1♂, 2♀, MTEC). Utah: Uintah County: 20 mi N of Vernal, 8400 ft, 21.vi.1988, R. Wharton (1♂, TAMU); Wasatch County: Strawberry Valley, 18.vii.1950 (1♂, FSCA). Wyoming: Fremont County: Union Pass Road, along rocky steam, 17.vii.1961, J.G. Chillcott (1♂, CNC).
Diagnosis. This species is very similar to C. celatus sp. nov. — males of both species are distinguished by possessing long setae on anteroventral to posteroventral surface of hind femur (Fig. 55)—but C. cilifemoratus differs in having a shorter arista-like stylus with broader apical lamella (cf. Figs 29 and 31), fore coxa mostly fuscous in lateral view (mostly to wholly yellow in C. celatus), foreleg with tarsomere 3 about three-quarters length of tarsomere 4 (tarsomere 3 about half length of tarsomere 4 in C. celatus; cf. Figs 41 and 42), and wing with anal lobe markedly widening before apex of R 1 (anal lobe markedly widening beyond apex of R 1 in C. celatus), and with a longer crossvein dm-m (cf. Figs 57 and 59).
Redescription. Male. Wing length 2.8–3.1 mm. Head: Frons wholly brown pruinose, with at most weak blue reflections. Face gray becoming whitish ventrally, narrowly triangular, about 1 ommatidium wide at clypeus.Antenna (Fig. 29) dark brown; scape long, subequal to combined length of pedicel and postpedicel; postpedicel oval, length subequal to width; arista-like stylus short (length subequal to head height), with large, wide (nearly as wide as long) apical black lamella, irregular in shape, usually somewhat flattened at apex but sometimes rather rounded at apex. Palpus small, elongate oval, brown. Thorax: Pleura dark brown with gray pruinosity; metepimeron concolorous with pleura, usually yellowish just above hind coxa. Legs: Foreleg: Yellow, except coxa mostly brown with gray pruinosity, femur brown on basal half (often light brown), tarsomere 1 brown dorsally at apex, tarsomeres 3–5 brown. Femur with very small yellow ventral setae on basal half. Tibia slender, sometimes with very small indistinct posterodorsal seta near 2/5. Tarsus (Fig. 42) with tarsomere 1 very short, about as wide as long. Tarsomere 2 long, subequal to length of tibia, very slightly bowed, with 2 fine curved anterior setae at apex (slightly shorter than tarsomere 3 length). Tarsomere 3 about three-quarters as long as tarsomere 4, slightly broadened, subrectangular, with longer pale setulae dorsally near apex. Tarsomere 4 dorsoventrally flattened and bowed, with longer pale dorsal setulae on apical half (longest at apex). Tarsomere 5 dorsoventrally flattened. Midleg: Coxa infuscated with yellow ground color visible, femur and tibia wholly yellow (tibia vaguely brown in some specimens), tarsus brown from apex of tarsomere 1. Femur with short (usually less than half femur width), slender yellow ventral setae. Tibia without specialized setae, inconspicuously flattened and bowed. Tarsus slightly longer than tibia. Tarsomere 1 subequal to combined length of tarsomeres 2–4, apex with 2 fine curved anterior setae (one long, one shorter). Tarsomere 2 with basal half slightly swollen and bearing 3 fine curved pale anterior setae. Tarsomere 4 with a few slightly longer setae (longest slightly broader than tarsomere) along anterior edge; long (about half tarsomere length) fine curved pale anterior seta at apex. Hindleg: Yellow, except coxa mostly to wholly infuscated, sometimes yellow apically, femur with most of apical half brownish, tibia and tarsus brown. Apical half of femur with anteroventral to posteroventral surface with dense, erect, long (longest greater than femur width) mostly yellow setae, posterior preapical seta absent (as in Fig. 55). Tibia with finer, denser ventral setae on basal half (length subequal to tibia width). Wing (Fig. 59): Narrow and elongated, anterior half or more with brown tinge. Very narrow and appearing petiolate at base, anal lobe markedly widening just before apex of R 1, posterior margin slightly excavated at M 4. Distal section of M 4 about 3X longer than crossvein dm-m. Abdomen: Usually wholly brown, sometimes tergite 2 yellow laterally. Hypopygium: Hypandrium broad with rounded apex in ventral view, apex pointed in lateral view. Postgonite apical lobes narrowly rounded, brown, each lobe darker brown apically and along margins.
Female. Wing length 2.3–2.5 mm. Similar to male except as follows: Head: Face wide, nearly parallel-sided, gray. Clypeus light gray. Antenna with postpedicel short, rounded with flattened apex; arista-like stylus unmodified. Palpus much larger, triangular, rounded apically, dark brown, with white setulae and brown setae. Thorax: Proepimeron with 1–2 small white hairs. Legs: Unmodified, without specialized setae. Fore coxa yellow with indistinct gray pruinosity in anterior view. Fore femur yellow. Hind femur yellow, slightly brown dorsoapically. Hind tibia yellow, becoming brown apically. Wing: Evenly light brown. Anal lobe broader, not constricted at base. Distal section of M 4 about 3.5X longer than crossvein dm-m. Abdomen: Tergite 2 with small yellow lateral spot at base, remaining tergites brown.
Distribution and seasonal occurrence. This species is known from Alaska and the Northwest Territories and at increasingly higher elevations southward to Colorado and Utah (Fig. 72). Adults have been collected from June to August.
Remarks. Harmston & Knowlton (1940) distinguished C. fuscitibialis based on the darker leg color, but leg color (especially fore coxa and femur) varies from light brown to dark brown. The viewing angle can affect how dark the legs appear, for example, in some specimens the fore coxa appears dark yellow in lateral view but dark brown in anterior view.
description: Published as part of Runyon, Justin B., 2024, Revision of the genus Calyxochaetus Bigot (Diptera: Dolichopodidae: Sympycninae), pp. 1-74 in Zootaxa 5539 (1) on pages 22-23, DOI: 10.11646/zootaxa.5539.1.1, http://zenodo.org/record/14240426