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

description: Calyxochaetus ornatus Parent
(Figs 109, 126, 134, 138, 148)
Calyxochaetus ornatus Parent, 1930: 106.
Calyxochaetus patellifer Parent, 1934: 136 syn. nov. Type material examined. Calyxochaetus ornatus: HOLOTYPE ♂, labeled: “MUSEUM PARIS/ MEXIQUE / ÉTAT DE JALISCO / ENVIRONS DE GUADALAJARA / L. DIGUET 1914”; “NOVEMBRE”; “TYPE [red label]”; “MNHN, Paris / ED11407” (MNHN) [photos examined].
Other material examined. GUATEMALA: Zacapa Department: San Lorenzo, 1800 m, 7–9.vii.1986, L. LeSage (1♂, CNC). MEXICO: Chiapas: San Cristobal de las Casas, 29.vii.1956, D.D. Linsdale (4♂, 1♀, EMEC); same data except, 8.viii.1957, J.A. Chemsak & B.J. Rannells (1♂, EMEC); same data except, 25.v.1969, 7087 ft, B.V. Peterson (1♂, CNC); same data except, 1.vi.1969, 7200 ft, Malaise (1♂, 3♀, CNC); 10 mi. NE San Cristobal de las Casas, 22.v.1969, 7500 ft, H.J. Teskey (1♂, CNC); Hidalgo: Tula, 16–17.i.1993, G.E. Bohart (3♂, 5♀, LACM); Jalisco: Guadalajara, 19.ix.1903, McClendon (2♂, FSCA); Mexico City: Mexico City, iii, iv, vi.1965, N.L.H. Krauss (1♂, USNM); Morelos: Cuernavaca, 10–12.xi.1987, F.D. Parker (1♂, 1♀, LACM).
Diagnosis. The very large lanceolate lamella on the arista-like stylus of males is diagnostic (Fig. 109).
Redescription. Male. Wing length 3.2–3.6 mm. Head: Frons brown pruinose with large glabrous shiny blue-violet spot on either side of ocellar tubercle. Face white-silver, nearly parallel-sided on ventral half, about 3 ommatidia wide at narrowest. Antenna (Fig. 109) brown, scape short and stout; postpedicel short and oval, about as long as wide; arista-like stylus with large lanceolate microtrichose lamella (as broad as postpedicel width) on apical half or more. Palpus small, elongate oval, brown with yellow apex. Thorax: Pleura brown with thick gray pruinosity; metepimeron yellow (rarely lightly infuscated). Scutellum with distinct blue-violet reflections medially. Legs: Foreleg: Yellow, except tarsus infuscated from near base of tarsomere 3. Tibia slender, sometimes with small slender posterodorsal seta near 1/3. Tarsomere 1 very short, nearly round. Tarsomere 2 longer than tibia, subequal to combined length of tarsomeres 3–4. Tarsomere 3 slightly more than half tarsomere 4 length, widened apically, with longer dorsoapical microsetulae. Tarsomere 4 slightly flattened, very slightly widened near base, with dense short pale hooked dorsal microsetulae (especially near base); lateral edges of dorsal surface with row of setae (length subequal to tarsomere width). Midleg: Yellow, except tarsus brown from near apex of tarsomere 1 (tarsomere 1 mostly brown in a few specimens). Tarsus (Fig. 126) with tarsomere 1 slender, about two-thirds tibia length, longer than combined length of tarsomeres 2–5. Tarsomere 2 subequal to combined length of tarsomeres 3–4, gradually widening to apex with pointed anteroapical lobe bearing short setulae. Tarsomere 3 wider than long, suboval and flattened, with longer anterior and ventral setulae (mostly white). Tarsomere 4 larger than tarsomere 3, flattened, asymmetrical, widest at base with anterior edge irregular and narrowing (sloping) to apex, with longer anterior and dense white ventral setulae (longest, densest posteroventrally). Tarsomere 5 slender, about as long as combined length of tarsomeres 3–4. Hindleg: Yellow, except tibia brownish apically, tarsus wholly brown. Tibia (Fig. 134) with posteroventral row of longer, slender setae on basal half, those nearest base longest. Wing (Fig. 138): Tinged light brown, slightly darker along anterior edge. Elongate oval and narrow, with anal area reduced; anal angle absent. Distal section of M 4 about 3X longer than crossvein dm-m. Abdomen: Tergites 2–3 largely yellow. Tergite 4 yellow ventrally near base (mostly yellow in a few specimens). Hypopygium: Postgonites with apical lobes bluntly rounded to obliquely truncated, shiny light to dark brown.
Female. Wing length 3.3–3.5 mm. Similar to male except as follows: Head: Face wider (subequal to postpedicel width), nearly parallel-sided, gray-silver with weak bluish hue. Antenna with postpedicel wider than long, usually subquadrate with apex flattened; arista-like stylus unmodified. Palpus larger, triangular, dark brown, narrowly yellowish apically and sometimes along margins. Thorax: Proepimeron with cluster of 2–8 small white hairs. Legs: Unmodified, without specialized setae. Wing: Evenly tinged light brown. Elongate oval. Anal area broader. Distal section of M 4 about 2.5X longer than crossvein dm-m. Abdomen: Tergites 2–3 with large yellow ventrolateral spots (but less yellow than in males). Tergite 4 with small yellow ventrolateral spot.
Distribution and seasonal occurrence. Known from the tropical highlands of Mexico and Guatemala (Fig. 148). Adults appear to be active year-round.
Remarks. The type specimens of C. patellifer (Mexico: Chiapas: San Cristobal de las Casas, 6.vii.1926, Dampf), deposited in the Zoologisches Museum und Institut, Hamburg, Germany (Parent, 1934), could not be located and were likely destroyed when the museum was bombed during World War II (M. Husemann, pers. comm.). Parent (1930, 1934) illustrated the fore and mid tarsi and wings of C. ornatus and C. patellifer but described C. ornatus from a male missing the arista-like stylus. There are no clear differences between the descriptions or illustrations of the legs and wings of both species (Parent 1930, 1934). Moreover, material examined from the type locality of both species (Guadalajara and San Cristobal de las Casas) match the holotype of C. ornatus and description of C. patellifer. Because of this, I consider these species to be conspecific.
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 63-64, DOI: 10.11646/zootaxa.5539.1.1, http://zenodo.org/record/14240426