Argentinomyia catabomba ( Williston, 1891 )

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 : 46-49

Argentinomyia catabomba ( Williston, 1891)

( Figs 24 , 25 and 96B )

Melanostoma catabombum Williston, 1891: 12 . Type locality: Mexico. Guerrero, Omiltemi , 8000ft and Amula , 6000ft. SYNTYPE 6 Males and 3 Females BMNH (Examined) . LECTOTYPE Male BMNH here designated. Refs.: Fluke, 1945 : 5 (Redescription), Fig. 2 (head)

Rhysops catabomba . Curran, 1937: 2 (key)

Rhysops catabomba . Fluke, 1945: 5

Rhysops catabomba . Thompson et al. 1976: 42

Melanostoma catabombum . Papavero & Ibañez-Bernal, 2003: 166

Argentinomyia catabomba . Mengual, 2020: 7

Melanostoma melanocerum Williston, 1891: 13 . Type locality: Costa Rica. Rio Sucio SYNTYPE 2 Females BMNH. LECTOTYPE Female BMNH here designated. (Examined). n. syn.

Rhysops melanocerum . Williston, 1907: 2

Rhysops melanocera . Curran, 1937: 2 (key)

Type material. LECTOTYPE. Adult Male, MEXICO. Guerrero, Omiltemi , 2438 m, 1.vii.1903, H. H. Smith ( BMNH, Previously SYNTYPE). “ LECTOTYPE / Melanostoma catabombum / det. A.L. Montoya 2023” . PARALECTOTYPES. Label with the same data as LECTOTYPE except (5♁, 3♀, BMNH Previously SYNTYPE). “ PARALECTOTYPE / Melanostoma catabombum / det. A.L. Montoya 2023”. MEXICO. Guerrero, Xucumanatlan , 1900 m, 1.vii.1903, H. H. Smith (8♁, BMNH, Previously SYNTYPE). “ PARALECTOTYPE / Melanostoma catabombum / det. A.L. Montoya 2023”. MEXICO. Guerrero, Amula (Note: Modern name of Amula is Almolonga), 1829 m, 1.vii.1903, H. H. Smith (3♁, BMNH, Previously ALLOTYPE). “ PARALECTOTYPE / Melanostoma catabombum / det. A.L. Montoya 2023”. Label with the same data as LECTOTYPE except (2♁, 1♀, AMNH 19161 , 19255 , in the USNM ENT, Previously COTYPE). “ PARALECTOTYPE / Melanostoma catabombum / det. A.L. Montoya 2023” . LECTOTYPE. Adult Female, COSTA RICA. Rio Sucio (Previously SYNTYPE). “ LECTOTYPE / Melanostoma melanocerum / det. A.L. Montoya 2023” . PARALECTOTYPE. COSTA RICA. Rio Sucio (1♀, BMNH, Previously SYNTYPE). “ PARALECTOTYPE / Melanostoma melanocerum / det. A.L. Montoya 2023” .

Length (n= 8): Body, 8–10 mm; Wings, 7.5–8.1 mm.

Diagnosis. Scape and basoflagellomere of equal length; wing hyaline, almost bare on basal 2/3 or more; protarsus dark; abdomen with rounded oblique yellow maculae on 3 rd to 4 th terga; surstylus brown with dorsal and ventral margins approximately of the same width in the whole length, shorter than broad; hypandrium narrowed laterally towards the apex; aedeagal lobe with apex acute.

Redescription. MALE. Head ( Fig. 24A ): Face black, sides of the frontal triangle and face thickly covered with uniform yellow golden pollen, leaving a linear spot in the median dorsal area of the antennae and a broad ventromedial vitta shining, somewhat metallic black. Gena semi-shining. Frontal triangle black pilose Ocellar triangle blue metallic with thin brownish pollen, pile black. Occiput with yellow hairs dorsally, long pile black, pollen and pile paler ventral. Antennae brownish orange, short, ratio 1.4:1.0:1.6, basoflagellomere largely blackish dorsal; scape about as long as the oval basoflagellomere, distinctly longer than pedicel; arista yellow-orange at base and dark on apical third. Thorax ( Fig. 24B–C ): Bronze, mesonotum shining, yellow pilose; with three brownish vittae on anterior half, the median one slender, side broadly brownish pollinose, pile yellow-brownish. Pleura of a similar colour in middle, more steel-blue ventral, posterior margin of anepisternum slightly reddish, grey pollinose. Scutellum shining steel-blue, yellowish pilose; fringe long and yellow. Wing ( Fig. 24C ): Diluted reddish, stigma brown, with a narrow cloudy-blackish macula at the tip, cells dm, cua 1 bare on basal 2/3 or more, cell cua bare on anterior 1/3; calypter white, border and fringe brownish; plumula white, halter orange yellowish, capitulum slightly yellowish. Legs ( Fig. 24C ): Yellow to reddish; pro- and mesofemora brownish basally; pro- and mesotarsi black, except basal segments reddish yellow; metafemur brown except yellow apically; metatibia brown except yellow on basal 1/4; basal two segments of tarsi yellow. Abdomen ( Fig. 24B ): Narrow, its greatest width at the distal end of the 3 rd tergum; opaque black; 1 st tergum and hypopygium shining metallic; 2 nd tergum metallic on antero-lateral margin, with lateral yellow maculae that run alongside and is narrow at apex; 3 rd and 4 th terga each with a pair of moderately large, rounded yellow maculae anteriorly, reaching the lateral margin; pile long and light yellow laterally; sterna blackish, yellow pilose; male genitalia: cercus yellow, surstylus brown, in lateral view ( Fig. 25A ) with dorsal and ventral margins approximately of the same width in the whole length, shorter than broad; hypandrium in ventral view ( Fig. 25C ) narrowed laterally towards the apex; aedeagal lobe in ventral view ( Fig. 25C ) with apex acute.

FEMALE ( Figs 24D–F ). Similar to male except for usual sexual dimorphism and differing in the frontal triangle and sides of face whitish-pollinose, with an opaque black cross-band, in addition to a pointed band of pollen extending medially. Thorax and scutellum moderately shining, greenish-blue; mesonotum with three darker vittae, the median one linear. Abdomen subopaque, black, 1 st to 5 th terga more shining; 2 nd tergum with a yellow macula on each side reaching anterior margin; the oval maculae of 3 rd and 4 th terga not touching lateral margin. Female of A. catabomba can be confused with A. CR-14, but differs from it by the pro- and mesofemora brownish basally; metafemur brown except yellow apically; pro- and mesotarsi with the three apical tarsomeres yellow. 2 nd tergum metallic on anterolateral margin, with lateral yellow maculae that run alongside and is narrow at the apex. 3 rd and 4 th terga each with a pair of moderately large, rounded yellow maculae anteriorly.

Taxonomic notes. Argentinomyia catabomba is characterized by the scape and basoflagellomere of equal length ( Figs 24A, C , D-F); protarsus dark ( Figs 24A, C , D-F); abdomen with rounded oblique yellow maculae on 3 rd to 4 th terga ( Figs 24B, E ). Argentinomyia catabomba is similar to the South American species A. lanei and A. berthae differing from them by the wing hyaline with costal cell bare on basal 3/4 or more and protarsus dark ( Figs 24 BC, E-F). A. catabomba can be confused with Argentinomyia CR-14, a species with pro- and mesofemora orange; metafemur is brown, only yellow on basal 1/3; pro- and mesotarsi with the three apical tarsomeres black ( Figs 24A, C , D-F); 2 nd tergum orange on basolateral 2/3, 3 rd and 4 th terga with oval macula extending on lateral margin ( Figs 24B, E ). Based on males, A. catabomba differs from A. berthae and A. lanei in having the surstylus in lateral view ( Fig. 25A ) with dorsal and ventral margins approximately of the same width in the whole length [versus surstylus with dorsal margin slightly concave and ventral margin slightly convex in A. berthae ( Fig. 19A ); surstylus with dorsal and ventral margins approximately of the same width in the whole length in A. lanei ( Fig. 41A )]; aedeagal lobe in ventral view, with acute apex in A. catabomba ( Fig. 25C ) and A. lanei ( Fig. 41C ) [versus aedeagal lobe circular, apex rounded in A. berthae ( Fig. 19C )] (see “differential diagnosis” under each species or key).

Remarks. According to FC Thompson (personal unpublished notes), Fluke (1945) keys out A. catabomba together with A. scitula ( Williston, 1888) and separated it by the “front tarsi wholly yellow”. However, FC Thompson, pointed out that this character is in conflict with Williston’s original description, who clearly indicated the “basal portion of protarsus is yellow” in A. scitula , then it is probable that Fluke meant to say protarsus is dark in A. catabomba , with only the basal segments reddish yellow ( Curran 1937).

A female specimen collected in Guatemala was misidentified as Rhysops vittithorax by Hull (CNC DIPTERA 112215) which is a synonym of A. longicornis (Walker, 1836) therefore we corrected the identification as A. catabomba .

When examining and comparing the syntype of Melanostoma melanocerum (Williston) (2 females) with the syntype of Melanostoma catabombum Williston (1 male) deposited in the BMNH, we found that they correspond to opposite sexes of the same species since both female and male have the same patterns of pollinosity on thorax and abdominal maculae are similar, with only the sexual dimorphism found in most species of the genus. Thus, based on examination of the syntype and due to the morphological evidence presented above, Melanostoma melanocerum is synonymized with A. catabomba .

Finally, Williston, 1891: 12 described Melanostoma catabombum based on six males and three females collected in Mexico, Guerrero, Omiltemi, 8000ft and Amula, 6000ft. The nine specimens comprise the type series deposited in the collection of the AMNH and BMNH labelled as “ Syntype ”, “ Allotype ” and “Cotype”. Curran (1937) and Fluke (1945) keyed out and provided a redescription to the species A. catabomba but did not select or designate a Lectotype. Therefore, to avoid assuming which specimen is the Holotype and objectively establish the identity of this taxon and consequently stabilize the nomenclature and universal interpretation of the name, one male specimen from the BMNH labelled “ Syntype ” Melanostoma catabombum / Williston, 1891 / “ MEXICO. Guerrero, Omiltemi / 2438 m, 1.vii.1903, H. H. Smith” is hereby selected and designated as the Lectotype. The remaining syntypes in the BMNH labelled “ Syntype ” Melanostoma catabombum / Williston, 1891 / “ MEXICO. Guerrero, Xucumanatlan, 1900 m, 1.vii.1903, H. H. Smith and MEXICO. Guerrero, Amula 1829 m, 1.vii.1903, H. H. Smith” as well as the ones in the AMNH labelled “ Syntype ” Melanostoma catabombum / Williston, 1891 / “ MEXICO. Guerrero, Amula 1829 m, 1.vii.1903, H. H. Smith” are consequently designated as Paralectotypes to ensure consistent interpretation of this name and have been so labelled. The arguments for selecting this specimen were: (1) it is in almost perfect condition and (2) corresponds exactly to the same type locality. Below the above criteria, Lectotype and Paratype are designated for Melanostoma melanocerum from two female Syntype specimens housed in the BMNH and labelled “ COSTA RICA. Rio Sucio”.

Geographical range. Argentinomyia catabomba (n= 66) is distributed in Costa Rica * (Cartago, Limón, Puntarenas, San José), Guatemala * (Antigua, Baja Verapaz, Panajachel), El Salvador * (San Salvador), Mexico (Chiapas, Guerrero, Mexico D.F., Oaxaca, Xalapa) and Panamá * (Chiriqui) ( Fig. 96B ). The species is endemic to the Mesoamerican domain, distributed at low and middle altitudes (94–2510 m) in the provinces: Chiapas Highlands (1550–2510 m), Pacific Lowlands (1900–2438 m), Puntarenas-Chiriquí (1200 m), Serra Madre del Sur (1829 m) , Trans-Mexican Volcanic Belt (2463 m) and Veracruzan (94 m).

Non-type material examined. COSTA RICA. Cartago, 9.852518, -83.923886, 1390 m, xi.1965, N.L.H. Krauss (1♁, USNM ENT 00036957); Rio Grande de Orosi, desde Administración hasta Sendero La Pava, 9,797 784, -83,925756, 1150–1600 m, 2.i.1997, R. Guzmán (2♁, INBioCRI 002537010–11); Limón, P.I.I A. Valle del Silencio, alrededor Refugio Sendero Circular, 9,297 345, -83,043913, 2450 m, 5.x.2003, R. Gonzales (1♁, INBioCRI 0003754850); …, 2420 m, 6.vi.1996, R. Villalobos (1♁, INBioCRI 000399294); Puntarenas, Quarry (Tajo) near Las Alturas Station, 8,856 123, -82,850287, 1064 m, 16.vii.1995, N. Norrbom (1♀, USNM ENT 00036947); Estación Altmira, 1 km S del Cerro Biolley, 1450 m, 28.vii.1995, R. Villalobos (1♀, INBioCRI 002322716); San José, F. Cementerio de la Maquina P.N. Chirripó, 2100–2500 m, 3.ii.1993, F. Quesada and M. Segura (2♁, INBioCRI 001208818; 001305772). GUATEMALA. Antigua, 14.558571, -90.729523, 1550 m, 23.vi.1923, E. G. Smith (1♀, CNC DIPTERA 112215) (Identified as Rhysops vittithorax by Hull and Rhysops sp. 19 by Vockeroth); Baja Verapaz, Cerca Purulhá, camino Pantín, 15,207 742, -90,176891, 1500 m, 22.ix.2005, José Monzón (2♁,Colección J. Monzón); Salamá, Camino Paten a Santa Rosa, 15,062 189, -90,353998, 1700 m, 15.vi.2007, José Monzón (2♁, Colección J. Monzon); Sololá, Panajachel, 14,740 962, -91,151845, 1750 m, 19.viii.1963, D.Q Cavagnaro, M.E. Irwen (1♀, CAS). EL SALVADOR. San Salvador, 13,696 903, -89,254923, 893 m, 8.vii.1963, D.Q Cavagnaro, M.E. Irwen (1♁, CAS). MEXICO. Chiapas, San Cristóbal de las Casas, L. C. Huitepec, 16.736812, -92.637332, 2510 m, 26.ii.2011, P. Sagot (12♁, 11♀, ECO-TAP-E); Zinacantan, Muktavits (Cerro Huitepec) 16,744 909, -92,682661, 2804 m, 15.vii.1976, D.E and J.A. Breedloe (1♁, 1♀, CAS); Mexico, Parque, along Lakes of Zempoala, 19.053873, -99.311982, 2463 m, 10-11.viii.1989, A.L. Norrbom, Sweeping on Dahlia imperiales (89 M12) (1♁, USNM ENT 00036950); D.F, L. Conradt (1♀, USNM ENT 00036958); Oaxaca, Km 188 in Valle Nacional, Road 29, 17.767761, -96.323867, 94 m, 29.vii.1992, M. Wood (1♀, CNC DIPTERA 112220); Xalapa, 19,543 487, -96,909959, 1450 m, 22.ii.1998, A. Freidberg (1♀, USNM ENT 01443748). PANAMÁ. Chiriqui, 2Km Santa Clara, Finca Hartmann S. 8.844832, -82.760761, 1200 m, 27.vi.1981, B. Gill (1♁, CNC DIPTERA 112216) (Identified as Rhysops sp. 19 by Vockeroth).

Figures

FIGURE 2. Differences in head morphology, male: A. Argentinomyia rugosonasa, frontal view; Argentinomyia longicornis: B. lateral view; C. frontal view; D. Argentinomyia bolivariensis, frontal view.

FIGURE 19. Argentinomyia berthae (Lima, 1946), male Neotype, genitalia. A. Whole genitalia, lateral view; B. Epandrium, dorsal view; C. Hypandrium, ventral view. Scale bars: 1 mm.

FIGURE 24. Argentinomyia catabomba (Williston, 1891), male (ECO–TAP–E 483): A. Head, frontal view; B. Dorsal view; C. Lateral view. Female (ECO–TAP–E 1715): D. Head, frontal view; E. Dorsal view; F. Lateral view (CNC DIPTERA 112220). Scale bars: 5 mm.

FIGURE 25. Argentinomyia catabomba (Williston, 1891), male genitalia. A. Whole genitalia, lateral view; B. Epandrium, dorsal view; C. Hypandrium, ventral view.

FIGURE 41. Argentinomyia lanei (Fluke, 1936), male genitalia. A. Whole genitalia, lateral view; B. Epandrium, dorsal view; C. Hypandrium, ventral view. Scale bars: 1 mm.

FIGURE 96. Geographical distribution of Argentinomyia species in Central America.