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

description: Calyxochaetus fortunatus (Wheeler)
(Figs 2, 78, 83, 89, 94)
Nothosympycnus fortunatus Wheeler, 1899: 52.
Calyxochaetus fortunatus: Parent (1930: 107).
Type material examined. HOLOTYPE ♂, labeled: “ Natrona,/ 8.1.93 Pa.”; “Type” (AMNH).
Other material examined. CANADA: Ontario: Orillia, 15.vii.1923, C.H. Curran (3♂, CNC; 1♂, USNM); Ottawa, 17.vi.1955, J.G. Chillcott (2♂, 1♀, CNC); same data except, 20.viii.1991, damp shaded ditch in Acer wood, J.R. Vockeroth (4♂, CNC); same data except, 28.viii.1991 (2♂, CNC); same data except, 31.viii.1991 (1♂, 2♀, CNC); Niagara Glen, 1.viii.1957, J.R. Vockeroth (1♀, CNC); Algoma District, Whiskey Bay, 24.vii.1988, RLH (3♂, 3♀, MTEC); same data except, 3.viii.1991 (1♂, 6♀, MTEC); same data except, 6.viii.1991 (1♂, 8♀, MTEC). New Brunswick: St. Andrews, 8.viii.1957, G.E. Shewell (1♂, 2♀, CNC); 8 mi. W Hillsborough, 26.vii.1991 (1♂, 5♀, MTEC). Quebec: Wakefield, 30.viii.1959, J.R. Vockeroth (1♀, CNC); Old Chelsea, 31.viii.1958, J.R. Vockeroth (1♂, CNC); same data except, 5.ix.1963 (1♂, CNC); Knowlton Lodge, 18–19.vii.1968, J.R. Vockeroth (3♂, 1♀, CNC); Lac Phillipe, 23.vii.1987, J.R. Vockeroth (1♂, CNC); same data except, 25.vii.1987 (1♂, CNC). USA: Connecticut: Litchfield County: Lake Waramaug, 23.vii.1923, ALM (1♂, USNM). Indiana: Parke County: Turkey Run, 27.vi.1933, ALM (1♂, USNM). Iowa: Allamakee County: 3 mi NW Lansing, 6.viii.2002, RLH (5♀, MTEC). Massachusetts: Berkshire County: Pittsfield, Springside Park, 366 m, 14.vii.2005, JBR & C. Delphia (3♂, 3♀, MTEC); Worcester County: Petersham, vii.1926, ALM (3♂, USNM). Michigan: Alcona County: McGillis Creek, 8 mi. W Mikado, 9.viii.1991, RLH (3♂, 1♀, MTEC); Alger County: Munising, 28.vii.1974, FCH (1♂, FSCA); Munising, Wagner Falls, 8.viii.1993, RLH (1♂, 4♀, MTEC); Houghton County: Sidnaw, 27.vii.1974, FCH (1♂, FSCA); Mason County: Scottville, 15.vii.1943, C.W. Sabrosky (1♂, USNM). New York: Tompkins County: Ithaca, 28.viii.1894 (1♂, FSCA). Ohio: Geauga County: Novelty Township, Chagrin River, 6.viii.1982, R.S. Zack (1♂, WSU). Pennsylvania: Huntingdon County: Perez Lake, 31.viii.2003, JBR (1♀, MTEC); same data except, 3.vii.2004 (1♂, MTEC); Shaver Creek, N40°42.084′ W77°53.243′, 24.vii.2006, JBR (2♂, MTEC); Luzerne County: Hazleton, viii.1930, Dietz (1♂, FSCA); Venango County: Richey Run, 0.5 mi E Emlenton, 23.viii.2003, JBR (1♂, 2♀, MTEC); Westmoreland County: (1♂, FSCA). Wisconsin: Adams County: Witch’s Creek, Dell Prairie, 24.viii.1984, RLH (1♂, 3♀, MTEC). Virginia: Dickenson County: Lick Branch, 2.5 mi E Clintwood, N37°09.50′ W82°24.15′, 11.vii.2008, JBR (2♂, 2♀, MTEC); Ramsey Fork, 3 mi. N Clintwood, 15.viii.2008, JBR (1♀, MTEC).
Diagnosis. Males can be recognized by the strongly swollen fore tibia (Fig. 83), posterior margin of the wing with a large lobe (Fig. 89), pleura yellow ventrally, and the shape of the arista-like stylus (Fig. 78).
Redescription. Male. Wing length 3.2–3.5 mm. Head: Frons with glabrous shiny blue-violet spot on either side of ocellar tubercle. Eyes broadly contiguous below antenna, face reduced to silver-white triangle below antennae; clypeus small, narrow, recessed silver-white triangle above palpus. Antenna (Fig. 78) brown, scape yellow-brown; scape laterally flattened, flared apically, shorter than postpedicel; postpedicel elongate oval, length variable but usually about 2X as long as wide; arista-like stylus with dense microtrichia, becoming gradually thicker throughout (at thickest, subequal to width of scape), apex rounded to weakly pointed; article 1 varying from one-quarter to one-half length of article 2. Palpus small, oval, brown with white apex. Thorax: Scutum with thick brown pruinosity, often yellowish above wing base. Postpronotal lobe and anterior notopleuron partly yellowish. Proepisternum mostly yellow. Pleura dorsally brown with gray pruinosity (appearing bluish), becoming yellow on ventral half especially along sutures, anepisternum usually with weak metallic green reflections; metepimeron wholly yellow. Legs: Foreleg (Fig. 83): Light yellow, except tarsus light brown from near middle of tarsomere 2. Tibia strongly swollen, narrowest at base and broadest subapically, with small slender posterodorsal seta at 1/3. Tarsomere 1 very short, about as long as wide. Tarsomere 2 with distally directed anterior seta at apex. Tarsomere 3 slightly bowed with apex broadened, with denser dorsal microsetulae on apical half. Tarsomere 4 with denser dorsal microsetulae. Midleg: Yellow, except tarsus brown from apical third of tarsomere 1. Femur with very short, slender, yellow ventral setae on basal half (longest about half femur width), with cluster of 2–4 small erect ventral preapical setae (apical-most seta largest). Tarsus similar to C. vegetus (Fig. 87) except more slender, with longer anterior setulae at apex of tarsomere 2 and on tarsomeres 3–4. Tarsomere 1 longer than combined length of tarsomeres 2–5. Tarsomere 2 subequal to combined length of tarsomeres 3–5 with apex very slightly widened, pointed anteriorly and bearing a few anteroapical setulae (slightly longer than tarsomere width). Tarsomeres 3–4 about as long as wide, with longer anterior setulae (slightly longer than tarsomere width). Hindleg: Yellow, except femur faintly brown on apical third, tibia faintly brown apically, tarsus brown from near middle of tarsomere 1. Femur ventrally with very short yellow-brown to black setae, with larger (subequal to femur width) ventral seta below preapical seta. Tibia with ventral setae near base not noticeably longer. Wing (Fig. 89): Very similar to C. cascadia sp. nov. except posterior margin with slightly shallower and broader excavation at apex of M 4, R 4+5 and M 1 less bowed beyond crossvein dm-m and slightly diverging at apex, distal section of M 4 slightly shorter (about 2.75X longer than crossvein dmm). Abdomen: Tergite 1 yellow laterally, brown dorsally. Tergites 2–3 mostly to wholly yellow. Tergite 4 usually yellow near base, sometimes mostly brown. Sternites yellow, sternite 5 yellow-brown. Hypopygium: Postgonites with apical lobes sharply pointed, varying from light to dark brown.
Female. Wing length 3.1–3.4 mm. Similar to male except as follows: Head: Face wider but relatively narrow (subequal to postpedicel width), nearly parallel-sided, slightly narrowing to clypeus, light gray. Antenna with scape and pedicel usually yellow-brown; postpedicel short, as wide as long, with round apex; arista-like stylus unmodified. Palpus much larger, triangular, rounded apically, brown with slight gray pruinosity, with longer yellow marginal setae and usually shorter black medial setae. Thorax: Proepimeron with usually 1 very small white hair (easily missed), sometimes with 2 or 3 very small hairs. Legs: Unmodified, without specialized setae. Hind tibia yellow. Hind tarsomere 1 mostly yellow. Wing: Elongate oval, posterior margin indistinctly excavated at apex of M 4. Abdomen: Tergite 2 mostly yellow, brown along posterior margin. Tergite 3 usually broadly yellow laterally, sometimes with small yellow lateral spot. Sternites yellow.
Distribution and seasonal occurrence. Known from eastern Iowa, northern Michigan east to New Brunswick and south to Virginia (Fig. 94). Adults have been collected June through early September.
Remarks. I have collected adults from quite dark areas in forests, for example, on vegetation beneath hemlocks and by sweeping beneath undercut stream banks.
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 40-41, DOI: 10.11646/zootaxa.5539.1.1, http://zenodo.org/record/14240426