Argentinomyia occidentalis Montoya & Wolff 2023, sp. nov.
Creators: name: Montoya, Augusto L.
name: Wolff, Marta
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Diptera
Syrphidae
Argentinomyia
Argentinomyia occidentalis

description: Argentinomyia occidentalis Montoya & Wolff sp. nov.
Proposed standard English name: Western long-antennae flower fly.
(Figs 5B, 7F, 52, 53, 90B)
Type material. HOLOTYPE. Adult Male, pinned, deposited at Colección Entomológica Universidad de Antioquia. Original label: “ COLOMBIA, Antioquia, Urrao, Páramo del Sol, 6,455 8333, -76,0939” / “ 3638-3800 m, 11.iii.2009, Leg J. Duque ”. “ HOLOTYPE / Argentinomyia occidentalis / Montoya & Wolff 2023” (CEUA 47448, dissected; left antenna broken and attached on specimen label). Identified as Argentinomyia sp. 5 by Montoya 2010. PARATYPE. COLOMBIA. Antioquia, Andes, Santa Rita, Páramo de Santa Rita, Laguna Santa Rita, 5.5499389, -75.9912444, 3611-3638 m, 3-5.iii.2010, M. Wolff Leg. (1♀, CEUA 47447).
Length (n= 2): Body, 8.1 mm; Wings, 7.5 mm.
Diagnosis. Abdomen with a pair of thin maculae (diamond-shape) covered by gray pollen on 3 rd to 4 th terga of male, the same type of macula on 2 nd to 5 th terga of female, maculae on all segments isolated from base and apex. Surstyle bent back as a Z in shape, no more than two times longer than wide; aedeagal lobe with acute apex.
Description. MALE. Head (Fig. 57A): Face shining black and somewhat brassy, golden pollinose and pilose. Gena black, golden pollinose and pilose. Frontal triangle golden pollinose, black pilose. Ocellar triangle black, brown pilose. Occiput golden pollinose. Antenna black, short, ratio 1.0:1.3:2.5, basoflagellomere at least twice as long as the pedicel and scape combined, black pilose; scape slightly curved basally, shorter than the basoflagellomere; arista black, slightly pilose. Thorax (Figs 57B–C): Metallic brownish-black, mesonotum with two faint yellow-whitish pollinose vittae on anterior half; mesonotum yellowish pilose, with lateral sides yellowish pollinose, yellow and black pile intermixed. Pleura shining black, silver dusted, except on bare area of anterior anepisternum, yellowgolden pilose. Scutellum shining, slightly rugose on apical half, pile yellow in addition to long marginal black pile. Wing (Fig. 57C): Hyaline, stigma brownish, microtrichose; calypter wholly golden yellowish; plumula, halter and capitulum yellowish. Legs (Figs 6F, 57C): Yellow to brown, yellow and black pilose, femora brown basally, except orange on apical 1/4; pro- and mesotibiae orange with a dark median ring; tarsi brown; metatibia extensively brown, only slightly orange on basal and apical 1/4. Abdomen (Figs 57B, 58D): Black metallic, bronze-green, 1 st to 2 nd terga black shining, with long lateral yellowish pile; 3 rd to 4 th terga with a pair of thin maculae cover with gray pollen, diamond shape, golden pilose, sterna metallic bronze-green with long yellow pilosity; male genitalia: surstylus yellow, in lateral view (Fig. 58A) bent back as a Z in shape, no more than two times longer than wide; hypandrium in ventral view (Fig. 58C) narrowed laterally towards the apex; aedeagal lobe in ventral view (Fig. 58C) with acute apex.
FEMALE (Figs 5B, 7F, 57D–F, 58E). Similar to male except for usual sexual dimorphism and differing in the abdomen with a pair of thin maculae covered with gray pollen on 2 nd to 4 th terga.
Taxonomic notes. Argentinomyia occidentalis sp. nov. is similar to A. rex having black antennae, pro- and mesotibiae orange with a dark median ring, but differs from it by the following combination of characters: Abdomen with a pair of thin maculae (diamond-shape) covered by gray pollen on 3 rd to 4 th terga of male (Fig. 57B), the same type of macula on 2 nd to 5 th terga of female, maculae on all segments isolated from base and apex (Fig. 57E). In A. rex the abdomen with lineate yellow maculae (Figs 68B, E). Based on males, A. occidentalis sp. nov. differs from A. rex in having the surstylus in lateral view (Fig. 58A, D) bent back as a Z in shape, no more than two times longer than wide [versus surstylus with dorsal and ventral margins approximately of the same width in the whole length, elongated, three to four times longer than broad in A. rex (Fig. 69C)]; aedeagal lobe in ventral view (Fig. 58C, D) with acute apex [versus aedeagal lobe circular with apex rounded in A. rex (Fig. 69C)] (see “diagnosis” under each species or key).
Etymology. The name Argentinomyia occidentalis (nominative, adjective feminine) is derived from the Latin word occidens, occidentis (Brown 1956: 567) which refers to the western. The name is given in allusion to the western distribution in Colombia.
Remarks. The type material was collected in two sampling events in the two Páramo complexes of Farallones de Citará and Páramo de Frontino, in the Western cordillera in Antioquia, Colombia (58F–G) in February 2009 and March 2010. A. occidentalis sp. nov. is predominantly distributed in mountainous areas and seems to be confined to high elevations between 3611-3800 m, where occurs in sympatry with Quichuana citara Montoya & Wolff 2017, A. altissima, Meropidia neurostigma Hippa, Platycheirus (Tuberculanostoma) antennatum (Fluke) and Styxia eblis (Hull). For a complete discussion about topographic characteristics and endemism in these type localities of the Western cordillera in Colombia see Montoya et al. (2017).
Geographical range. Argentinomyia occidentalis sp. nov. (n= 2) is confined to the eastern slope of the Western Cordillera and is known only from two localities in Colombia (Antioquia) (Fig. 90B). The species is present at high altitudes (3611-3800m) in the Northern Andes domain and Cauca province.
description: Published as part of Montoya, Augusto L. & Wolff, Marta, 2023, Taxonomic revision of the Neotropical genus Argentinomyia Lynch-Arribálzaga, 1891 (Diptera: Syrphidae), with description of 16 new species, pp. 1-157 in Zootaxa 5234 (1) on pages 98-101, DOI: 10.11646/zootaxa.5234.1.1, http://zenodo.org/record/7609993