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

description: Calyxochaetus furcatus (Van Duzee)
(Figs 113, 130, 147)
Nothosympycnus furcatus Van Duzee, 1929: 29.
Nothosympycnus unipilus Van Duzee, 1929: 29 syn. nov.
Calyxochaetus loewii Parent, 1930: 104 syn. nov.
Calyxochaetus furcatus (Van Duzee): Robinson (1970: 39).
Calyxochaetus unipilus (Van Duzee): Robinson (1970: 40).
Type material examined. Nothosympycnus furcatus: HOLOTYPE ♂ collected in Guatemala, labeled: “ElSalto/ Antigua/ Guat”; “JM Aldrich/ Coll V-1-26”; “Type No./ 41044/ U.S. N.M.”; “ Nothosympycnus / furcatus / Holotype. VanDuzee” (USNM).
Nothosympycnus unipilus: HOLOTYPE ♂ collected in Guatemala, labeled: “Guat/ ElSalto/ Antigua”; “JM Aldrich/ Coll V-1-26”; “Type No./ 41043/ U.S. N.M.”; “ Nothosympycnus / unipilus / Holotype.VanDuzee” (USNM).
Calyxochaetus loewii: HOLOTYPE ♂, labeled: “MUSEUM PARIS/ COSTA RICA / Paul SERRE 1920”; “ Calyxochaetus / Loewii / Par ”; “TYPE [red label]” (MNHN).
Other material examined. COSTA RICA: San Jose, “V:15.VII”, H. Schmidt (2♂, USNM); San Jose, Escazu, 8.ii.1987, G.E. Bohart (1♂, 1♀, LACM); San Jose, iii.1915 (1♂, AMNH). USA: Arizona: Cochise County: Garden Canyon, Huachuca Mts, 5300 ft, 16.iv.2003, JBR & RLH (1♂, MTEC); South Fork Cave Creek, Chiricahua Mts, 5235 ft, 24.iv.2002, RLH & JBR (1♂, 2♀, MTEC); same data except, 17.iv.2003 (1♂, MTEC); same date except, N31°52.43′ W109°10.98′, 5.iv.2016 (1♂, MTEC); same date except, N31°52.70′ W109°10.69′, 6.iv.2011, JBR (1♂, CNC; 4♂, MTEC); Graham County: Stockton Pass, seepage below Shake Spring, 31.v.1991, B.J. Sinclair (1♂, CNC); Pima County: Madera Canyon, 23.vi.1982, RLH (1♂, 3♀, MTEC); Santa Cruz County: Madera Canyon, 5100 ft, 25.iv.2001, RLH & JBR (1♂, MTEC). New Mexico: Catron County: Whitewater Canyon, 1.vi.1972, Malaise, W.W. Wirth (2♂, USNM).
Diagnosis. The form of the mid tarsus in males is distinct (Fig. 130).
Redescription. Male. Wing length 2.6–3.1 mm. Head: Frons with large glabrous shiny blue-violet spot on either side of ocellar tubercle. Face varying from white-silver with hint of yellow to golden yellow, nearly parallel-sided on ventral half, 2–3 ommatidia wide at narrowest. Antenna (Fig. 113) dark brown; scape slightly shorter than postpedicel; postpedicel elongate oval, about 1.5X as long as wide; arista-like stylus rather short (subequal to head height), unmodified but article 2 inconspicuously thickened at base. Palpus small, elongate oval, brown with apex yellow. Thorax: Pleura brown with thick gray pruinosity; metepimeron mostly yellow but very weakly infuscated. Scutellum with distinct blue-violet reflections medially. Legs: Foreleg: Yellow, except tarsus becoming brown from near middle of tarsomere 3. Tibia slender, without posterodorsal seta near 1/3. Tarsomere 1 very short, nearly round. Tarsomere 2 slightly shorter than tibia, subequal to combined length of tarsomeres 3–5. Tarsomere 3 two-thirds tarsomere 4 length, with longer dorsal microsetulae at apex. Tarsomere 4 slightly flattened dorsally, with short hooked dorsal microsetulae, slightly larger setulae along dorsal edges; row of short setulae across apex. Midleg: Yellow, except coxa often with hint of infuscation, tarsus mostly or wholly brown. Tarsus (Fig. 130) slightly longer than tibia. Tarsomere 1 slightly bowed, greater than half tibia length, slightly longer than combined length of tarsomeres 2–5. Tarsomeres 2–3 flattened, with long thin anteroapical projection bearing a few longer setulae. Tarsomeres 3–4 with longer (about 2X tarsomere width) posterior setae. Tarsomere 4 flattened with shorter and broader anteroapical lobe bearing short setulae, notched apically. Hindleg: Yellow, except coxa often with hint of infuscation, femur usually light brown distally, apex of tibia brown, tarsus brown. Tibia without specialized setae. Wing: Evenly tinged light brown. Elongate oval and rather narrow, with anal area reduced. Distal section of M 4 about 3X longer than crossvein dm-m. Abdomen: Tergites 2–3 yellow laterally. Tergite 4 sometimes yellow at base, remaining tergites dark brown. Hypopygium: Postgonites with apical lobes light brown, slender with rounded apex. Hypandrium with apex acuminate but folded over ventrally, hook-like.
Female. Wing length 2.9–3.2 mm. Similar to male except as follows: Head: Face wider (subequal to postpedicel width), nearly parallel-sided, gray-silver. Antenna with postpedicel about as wide as long, irregularly rounded. Palpus larger, triangular, rounded apically, brown-yellow. Thorax: Proepimeron with cluster of 3–4 small white hairs. Legs: Unmodified. Hindleg with femur, tibia and tarsomere 1 more yellow. Wing: Broader with larger anal area. Distal section of M 4 about 2.5X longer than crossvein dm-m. Abdomen: Tergites 2–3 with less yellow, sometimes reduced to small lateral spots.
Distribution and seasonal occurrence. Known from southern Arizona and New Mexico, Guatemala and Costa Rica (Fig. 147). In the USA, adults were collected from April to June; in Central America, adults were collected in February and May.
Remarks. Van Duzee (1929) described C. unipilus from a male specimen missing the arista-like stylus and middle legs and distinguished this species from C. furcatus based on the fore tarsomere 3 having a long hair below (absent in C. furcatus), yellow cerci (black in C. furcatus), and a silvery white face (yellowish in C. furcatus). Examination of the holotype revealed that the hair on fore tarsomere 3 appears to be a piece of debris (and present only on the right leg). Moreover, across the male specimens examined, the face color varies from silvery white (with a hint of yellow) to golden yellow. Van Duzee (1932) redescribed C. furcatus using additional material and reported the cerci were yellow and not black. The types of both species were collected at the same place and date, and I can find no differences between them or the holotype of C. loewii.
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 58-59, DOI: 10.11646/zootaxa.5539.1.1, http://zenodo.org/record/14240426