Argentinomyia norrbomi 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 norrbomi

description: Argentinomyia norrbomi Montoya sp. nov.
Proposed standard English name: Norrbom’s long-antennae flower fly.
(Figs 4J, K, 8B, 9A, 55, 56 and 93D)
Type material. HOLOTYPE. Adult male, pinned, deposited at National Museum de Natural History. Original label: “ BRAZIL, Paraná ” / “Palmas, Linha Alegría, Fazenda Cerro Chato, -26.50252, -51.67033, 1224 m, Malaise en la cima de campo; 3-4.iii.2015, M. Savaris; Allen L. Norrbom ” “ HOLOTYPE / Argentinomyia norrbomi / Montoya 2023” (USNM ENT 01443832). PARATYPE. BRAZIL. Label with the same data as Holotype (7♁, 5♀, USNM ENT 01443831, 6 ♁, 1♀, DZUP).
Length (n= 3): Body, 5.8–6.2 mm; Wings, 4.3–4.7 mm.
Diagnosis. Face with four or more distinct transverse grooves above the tubercle; frontal prominence is not greatly produced; male eyes widely dichoptic; legs yellow, except metafemur black on apical 1/2; abdomen with a pair of basal maculae on 2 nd and 3 rd terga extended only the apical 1/2 and 1/4, respectively; surstylus with dorsal margin slightly concave and ventral margin slightly convex; apex of hypandrium (superior lobes) in ventral view elongated, about 3× longer than wide.
Description. MALE. Head (Figs 4J, K, 9A, 55A): Face black, entirely covered with white pollen and pile except for a median vitta; tubercle low and with five very faint depressed lines immediately above tubercle. Frontal triangle polished with coppery reflections, extremely wide and with white pile. Frontal prominence is not greatly produced; eyes widely dichoptic; occiput white pilose and pollinose. Antenna orange, long, ratio 3.0:1.0:1.5, scape extremely long, about as long as the pedicel and basoflagellomere; arista yellow at base and dark on apical 1/3, bare. Thorax (Figs 55B–C): Black, mesonotum highly polished, short white pilose; with a coppery pollinose vitta on anterior half, pile white. Pleura shiny black, yellow pilose and pollinose. Scutellum black, polished, with two rugose depressions near the tip, pile entirely yellow. Wing (Fig. 55C): Hyaline, slightly yellowish, stigma yellow, microtrichose, except cell c bare basal 2/3, cells bm and r only slightly bare basally, cell cua bare; calypter wholly yellow; plumula yellow; halter yellow, capitulum yellow. Legs (Fig. 55C): yellow, except metafemur black on apical 1/2; only metafemur brownish on apical 1/2; tarsomeres orange brownish, orange pilose. Abdomen (Fig. 55B): Black, parallel-sided, 2 nd tergum black, 3 rd tergum with a basal pair of elongate yellow maculae reaching the apical 5/6; 4 th tergum with a pair of basal maculae occupying 1/3 the tergum length; pile all yellow; male genitalia: surstylus in lateral view (Fig. 56A) with dorsal margin slightly concave and ventral margin slightly convex, shorter than broad; apex of hypandrium (superior lobes) in ventral view (Fig. 56C) elongated, about 3× longer than wide; aedeagal lobe in ventral view (Fig. 56C) circular, apex rounded.
FEMALE (Figs 8B, 9A, 55D–F). Very similar to male but the frontal triangle is wider and greyish pollinose, abdomen with a pair of basal maculae on 2 nd and 3 rd terga extended only the apical 1/2 and 1/4, respectively. Female of A. norrbomi sp. nov. is similar to A. testaceipes but differs from it by the face with four or more distinct transverse grooves above the tubercle. Frontal prominence not greatly produced. Legs yellow, except metafemur black on apical 1/2. Abdomen with orange maculae. In A. testaceipes the face with a low tubercle, with no distinct transverse grooves above the tubercle. Frontal prominence greatly produced. Legs yellow. Abdomen metallic, without orange maculae.
Taxonomic notes. Argentinomyia norrbomi sp. nov. is differentiated from A. testaceipes by the following combination of characters: Face with four or more distinct transverse grooves above the tubercle; frontal prominence not greatly produced (Figs 55A, D); legs yellow, except metafemur black on apical 1/2 (Figs 55A, C, D, F); abdomen with orange maculae (Figs 55B, E). In A. testaceipes face without transverse grooves above the tubercle; frontal prominence greatly produced (Figs 81A, D); metafemur yellow (Figs 81A, C, D, F); abdomen metallic, without orange maculae (Figs 81B, E). Based on males, A. norrbomi sp. nov. differs from A. testaceipes in having the surstylus in lateral view (Fig. 56A) with dorsal margin slightly concave and ventral margin slightly convex [versus surstylus with dorsal and ventral margins approximately of the same width in the whole length in A. testaceipes (Fig. 82A)]; apex of hypandrium (superior lobes) in ventral view (Fig. 56C) elongated, about 3× longer than wide [apex of hypandrium short, as long as wide in A. testaceipes (Fig. 82C)] (see “diagnosis” under each species or key).
Etymology. The specific epithet of this species is a Latinized noun in the genitive case of the last name ‘Norrbom’ in honor of Allen L. Norrbom, a research entomologist at the USDA-ARS-Systematic Entomology Laboratory, who collected the type series of this species in Palmas, Linha Alegría, Fazenda Cerro Chato. The species is dedicated to him in gratitude for his hospitality and support during my internship (ALM) at the Smithsonian Institution in 2018.
Remarks. I (ALM) received the specimens of A. norrbomi sp. nov. from Allen L. Norrbom and the first impression was that they corresponded to A. testaceipes. However, when studied more thoroughly noticed the presence of yellow legs, except for a metafemur black on apical 1/2 and abdomen with elongated yellow maculae reaching the apical 5/6. The characteristic that most caught the attention was the male genitalia with elongated superior lobes. In consequence, when comparing it with specimens of A. testaceipes, it was concluded that this very special and marvelous specimen turned out to be a previously undescribed species.
Geographical range. Argentinomyia norrbomi sp. nov. (n= 28) is exclusively distributed in Serra da Fartura in Brazil (Paraná) (Fig. 93D). The species is endemic to Paraná domain (1224 m), occurring in sympatry with A. plaumanni sp. nov. throughout the middle elevations of southeastern Brazil, particularly in the Atlantic Forest where they appear to be widely distributed, but rare and less abundant (Paraná Forest 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 96-98, DOI: 10.11646/zootaxa.5234.1.1, http://zenodo.org/record/7609993