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

description: Calyxochaetus remifer sp. nov.
(Figs 1, 110, 118, 128, 142, 148)
Type material. HOLOTYPE ♂, labeled: “ MEXICO B.C. Sur/ Guerrero Negro / II-24-74 / G.E. Bohart ”; “HOLOTYPE/ Calyxochaetus / remifer / J.B. Runyon [red label]” (LACM) (Fig. 142).
Other material examined. MEXICO: Baja California: ca 28.665° -113.594°, at a desert seep, on seep monkeyflowers at night, 23.xi.2023 [photos examined: https://www.inaturalist.org/observations/192507313].
Diagnosis. The very large, elongate oval lamella on the arista-like stylus (Fig. 110) and form of the fore tarsus (Fig. 118) in males are unique in Calyxochaetus.
Description. Male. Wing length 3.4 mm. Head: Frons brown pruinose with large glabrous shiny blue-violet spot on either side of ocellar tubercle. Face white-silver, very narrow, about one ommatidium wide at narrowest. Antenna (Fig. 110) brown, scape slightly shorter than postpedicel; postpedicel short and oval, slightly longer than wide; arista-like stylus with large elongate oval microtrichose apical lamella (subequal in size to postpedicel). Palpus not visible. Thorax: Pleura brown with thick gray pruinosity, sclerite below halter yellowish; metepimeron mostly yellow, lightly infuscated on about dorsal half. Scutellum with distinct blue-violet reflections medially. Legs: Foreleg: Yellow, except tarsus brown from apex of tarsomere 3. Tibia slender, without outstanding setae. Tarsus (Fig. 118) with tarsomere 1 very short, nearly round. Tarsomere 2 slightly more than half tibia length, about half of combined length of tarsomeres 3–5. Tarsomere 3 short (about 2X length of tarsomere 1) and slightly broadened apically. Tarsomere 4 long (about 4X tarsomere 3 length) slightly flattened, broader, and rounded on basal third (oar-shaped), with dense short pale hooked dorsal microsetulae near base, lateral edges of dorsal surface with row of larger setae. Midleg: Yellow, except coxa infuscated at base, tarsomere 5 brown. Tarsus (Fig. 128) with tarsomere 1 slightly more than half tibia length, longer than combined length of tarsomeres 2–5. Tarsomere 2 rather short and flattened, subequal to combined length of tarsomeres 3–4, gradually widening to apex with pointed anteroapical lobe bearing short setulae. Tarsomere 3 wider than long, subtriangular and flattened, pointed anteriorly with a few anterior setulae. Tarsomere 4 larger than tarsomere 3, flattened, with wider anterior lobe, with a few anterior setulae and some white posteroventral setulae. Tarsomere 5 slender, slightly longer than combined length of tarsomeres 3–4. Hindleg: Yellow, except tarsus yellow-brown. Tibia with two long (about 2X tibia width), slender ventral setae at base. Wing: Hyaline. Similar to C. ornatus (Fig. 138), except anal area slightly broader. Distal section of M 4 about 3X longer than crossvein dm-m. Abdomen: Tergites 2–3 largely yellow. Tergite 4 brown-yellow.
Female. Unknown.
Distribution and seasonal occurrence. Known from southern Baja California and northern Baja California Sur, Mexico (Fig. 148). The holotype was collected in February and adults were photographed in November.
Remarks. This species seems related to C. ornatus and C. tohono sp. nov., based on the form of the fore and mid tarsus. In Baja California, many adults were observed on leaves of seep monkeyflowers at night (Chloe and Trevor Van Loon, pers. comm.) (Fig. 1).
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 66-68, DOI: 10.11646/zootaxa.5539.1.1, http://zenodo.org/record/14240426