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

description: Calyxochaetus coloradensis sp. nov.
(Figs 32, 44, 47, 66, 71)
Type material. HOLOTYPE ♂, labeled: “ Fairplay, Colo./ Aug. 8, 1968 / F. C. Harmston ”; “HOLOTYPE/ Calyxochaetus / coloradensis / J.B. Runyon [red label]” (CAS) (Fig. 66). PARATYPES: USA: Colorado: Same data as holotype (1♂, FSCA); same data except, 19.v.1966 (2♂, CAS).
Diagnosis. This species can be distinguished by the abdomen wholly dark brown, fore coxa and basal half of fore femur fuscous, foreleg with tarsomeres 2 and 3 subequal in length (Fig. 44), and the arista-like stylus with small, narrow apical lamella (Fig. 32).
Description. Male. Wing length 2.7–2.8 mm. Head: Frons with thick brown pruinosity, without metallic reflections. Face gray becoming whitish ventrally, narrowly triangular, about 1 ommatidium wide at clypeus.Antenna (Fig. 32) dark brown; scape long, subequal to combined length of pedicel and postpedicel; postpedicel oval, about as long as wide; arista-like stylus about as long as height of head, with apical lamella small, narrowly spatulate. Palpus small, oval, light brown with yellow setulae and brown setae. Proboscis brown. Thorax: Pleura dark brown with gray pruinosity; metepimeron concolorous with pleuron. Legs: Foreleg: Coxa fuscous with slightly gray pruinosity and white setae, femur fuscous on basal half or more, tarsomere 1 narrowly dark brown at apex, tarsus brown from apex of tarsomere 2. Tibia slender, sometimes with very small indistinct posterodorsal seta near 2/5. Tarsus (Fig. 44) with tarsomere 1 very short, about as wide as long. Tarsomere 2 about 1/2 length of tibia and subequal in length to tarsomere 3, with 2 fine yellow anterior setae at apex (greater than half tarsomere 3 length). Tarsomere 3 about 1.5X longer than tarsomere 4, with short pale dorsal setulae on apical half. Tarsomere 4 with short pale dorsal setulae on apical half. Tarsomere 5 dorsoventrally flattened. Midleg: Yellow, except coxa concolorous with pleuron, tibia light brown, tarsus brown from apex of tarsomere 1. Femur with a few very short slender yellow ventral setae near middle. Tibia without specialized setae. Tarsus longer than tibia. Tarsomere 1 slightly less than combined length of tarsomeres 2–5, apex with 2 fine curved anterior setae. Tarsomere 2 (Fig. 47) with basal third slightly swollen, bearing 3 fine curved pale anterior setae. Tarsomere 4 with long (slightly shorter than tarsomere length) fine curved pale anterior seta at apex. Tarsomere 5 with about 3 short fine setae along anterior edge. Hindleg: Yellow, except coxa concolorous with pleura, becoming yellowish apically, femur with apical fourth light brown, tibia light brown at base and becoming browner apically, tarsus brown. Apical half of femur with anteroventral row of long (longest greater than femur width) yellow setae; apical-most seta in row brown, posterior preapical seta absent. Tibia with row of finer, denser ventral setae on basal half (length subequal to tibia width). Wing: Similar to C. hardyi (Fig. 58) except: Anterior half or more with brown tinge. Anal lobe nearly straight and evenly widening until just before apex of M 4. Wing slightly broader on apical third. Distal section of M 4 about 3.5X longer than crossvein dm-m. Abdomen: Wholly dark brown.
Female. Unknown.
Distribution and seasonal occurrence. Known only from the type locality of Fairplay, Colorado (Fig. 71), from adults collected in May and August.
Etymology. Named after the state of Colorado.
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 24-26, DOI: 10.11646/zootaxa.5539.1.1, http://zenodo.org/record/14240426