Argentinomyia occidentalis Montoya & Wolff, 2023

Montoya, Augusto L. & Wolff, Marta, 2023, Taxonomic revision of the Neotropical genus Argentinomyia Lynch-Arribálzaga, 1891 (Diptera: Syrphidae), with description of 16 new species, Zootaxa 5234 (1), pp. 1-157 : 98-101

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 .

Figures

FIGURE 5. Female postabdomen. A. Lateral view of Argentinomyia norrbomi sp. nov.; B. Posterior view of the abdominal apex of Argentinomyia occidentalis sp. nov.; C. Dorsal view of distended abdomen of Argentinomyia luculenta. Abbreviations: Ap: apodeme of epiproct; Cer = Cercus; Ep: Epiproct; Hp: Hypoproct; Scl: sclerotized area; Sper: Spermatheca; Tg: tergite. Scale bars: 0.05 mm.

FIGURE 6. Differences in antennae morphology, dorsal view: A. Argentinomyia luculenta (♀); B. Argentinomyia testaceipes (♀); C. Argentinomyia catabomba (♀); D–G. Talahua fervida (♁): D. Head, frontal view, E. Metacoxa pile tuft, ventral view, F. Scutellum emarginated, dorsal view, G. Genitalia, lateral view; H. Argentinomyia CR-18 (♁); I. Argentinomyia sagoti sp. nov. (♀); J. Metasternum of Melanostoma sp.; K. Scutellar pile of Argentinomyia rex; L. Antennal cavities broadly confluent of Xanthandrus sp. Scale bar: 1 mm.

FIGURE 7. Schematic drawings showing colouration patterns of the posterior leg, lateral view.A. Argentinomyia crenulata; B. Argentinomyia longicornis; C. Argentinomyia ivani sp. nov.; D. Argentinomyia spinifemorata sp. nov.; E. Detail of black ring or smudge on the apical margin of metafemur of Argentinomyia praeusta; F. Argentinomyia occidentalis sp. nov.

FIGURE 52. Argentinomyia neotropica (Curran, 1937), male genitalia. A. Whole genitalia, lateral view; B. Epandrium, dorsal view; C. Hypandrium, ventral view. Scale bars: 1 mm. D. Natural habitus of a female specimen in Magdalena Partido, Buenos Aires Province, Argentina (iNaturalist catalogue number 6307133; https://www.inaturalist.org/observations/6307133). Photo taken by ©Gerónimo Martín Alonso.

FIGURE 53. Argentinomyia nigrans (Fluke, 1945), male (USNM ENT 01384670): A. Head, frontal view; B. Dorsal view; C. Lateral view. Female (USNM ENT 01406441): D. Head, frontal view; E. Dorsal view; F. Lateral view. Scale bars: 5 mm.

FIGURE 57. Argentinomyia occidentalis sp. nov., male Holotype (CEUA 47448): A. Head, frontal view; B. Dorsal view; C. Lateral view. Female (CEUA 47447): D. Head, frontal view; E. Dorsal view; F. Lateral view. Scale bars: 5 mm.

FIGURE 58. Argentinomyia occidentalis sp. nov., male genitalia. A. Whole genitalia, lateral view; B. Epandrium, dorsal view; C. Hypandrium, ventral view; D. Male genitalia, lateral view; E. Female abdomen, posterior view, detail of maculae on 4th and 5th tergum. Scale bars: 1,5 mm. F–G. Type localities. F. Páramo Santa Rica in Andes Antioquia, Colombia. Photo taken by ©Augusto L. Montoya; G. Páramo del Sol in Urrao Antioquia, Colombia. Photo taken by ©Esteban Domínguez.

FIGURE 68. Argentinomyia rex (Fluke, 1945), male genitalia. A. Whole genitalia, lateral view; B. Epandrium, dorsal view; C. Hypandrium, ventral view. Scale bars: 1 mm.

FIGURE 69. Argentinomyia rugosonasa (Williston, 1891), male: A. Head, frontal view (INBio CRI 002452405); B. Dorsal view (ECO–TAP–E 24469); C. Lateral view (INBio CRI 002452405). Female (INBio CRI 0003753634): D. Head, frontal view; E. Dorsal view; F. Lateral view. Scale bars: 5 mm. [Note: The coloration of female legs in figure 69D is mainly due to the conservation of the specimen]

FIGURE 90. Geographical distribution of Argentinomyia species in the Tropical Andes.