Argentinomyia crenulata ( 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 : 50-53

Argentinomyia crenulata ( Williston, 1891)

( Figs 26 , 27 and 91C )

Melanostoma crenulatus Williston, 1891: 12 . Type locality: Mexico. Guerrero, Xucumanatlan , 7000ft and Omiltemi , 8000ft. SYNTYPE 8 Males BMNH (Examined) . LECTOTYPE Male BMNH here designated. Refs.: Williston, 1891: 12 pi. 1: 5 (Habit) 5a–b (head); Fluke, 1945: 5 ( Fig. 3 , female head, lateral view)

Melanostoma crenulatum . Cooper & Cumming, 1993: 61

Rhysops crenulata . Curran, 1937: 2 (key)

Rhysops crenulata . Fluke, 1945: 5

Rhysops crenulatus . Thompson et al. 1976: 42

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

Argentinomyia crenulata . Montoya, 2016: 460

Type material. LECTOTYPE. Adult Male, MEXICO. Guerrero, Xucumanatlan ( Note : The correct way of Xucumanatlan is “ Xocomanatlan ” and the locality Xocomanatlan / Chilpancingo de Los Bravos ) 1900 m, 1.vii.1903, H.H. Smith ( BMNH, Previously SYNTYPE). “ LECTOTYPE / Melanostoma crenulatus / det. A.L. Montoya 2023” . PARALECTOTYPES Same data as LECTOTYPE except (7♁, BMNH, 1♀ CNC No. 19318, Previously SYNTYPE. “ PARALECTOTYPE / Melanostoma crenulatus / det. A.L. Montoya 2023”. MEXICO. Guerrero, Omiltemi ( Note : Modern name of Omilteme is Omiltemi ) 2438 m, 1.vii.1903, H.H. Smith (1♀, USNM ENT 00019255 , Previously COTYPE). “ PARALECTOTYPE / Melanostoma crenulatus / det. A.L. Montoya 2023”.

Length (n= 7): Body, 7.3–8.5 mm; Wings, 7.0– 7.6 mm.

Diagnosis. Seven or eight narrow, shallow, transverse grooves above the tubercle and sides of the face with a thin white line of pollen; antennae elongate, scape longer than pedicel and basoflagellomere, pedicel and basoflagellomere about equal in length; wings with two short medial transverse brown fasciae on anterior crossvein; metafemur and protibia black, black pilose; abdominal maculae metallic; surstylus with dorsal and ventral margins approximately of the same width in the whole length, shorter than broad.

Redescription. MALE. Head ( Fig. 26A ): Face shining black; a slender white line of pollen extends from the inner side of each antenna and slightly curves outward to the oral margin; mid-vitta shining, bare, with seven or eight shallows, transverse grooves; a triangular white spot at the ventrolateral sides of the antennal insertion; three small spots of white pollen along the orbital margin, the lowest one extended diffusely to oral margin. Frontal triangle opaque black dorsally, shining ventrally, with pile short, black. Gena shining black with thin, more whitish pollen, pile white. Ocellar triangle black with thin yellowish pollen, pile black. Occiput shining blue-black, lower occiput heavily coated with white pollen and pile. Antenna yellowish or reddish, long, ratio 1.2:1.3:2.1, black-brown, scape as long as pedicel and basoflagellomere together, scape and pedicel about equal length; basoflagellomere black, more than twice as long as wide, obtusely pointed; arista black, bare. Thorax ( Figs 26B–C ): Black or bluish-black bronze, mesonotum moderately shining; with two yellowish pollinose vittae on anterior half, pile yellow, becoming slightly dark brown on sides of notopleura and postalar callus. Pleura mostly thinly grayish-brown pollinose, dark brown on anepimeron. Scutellum more steel-wine, yellow pilose; fringe short and yellow. Wing ( Fig. 26C ): Brownish, stigma yellow, membrane microtrichose, only slightly bare on basal area of cell c, cells bm and r bare on basal 2/3 and 1/3, respectively, cell cua bare on anterior 1/3, two short medial transverse brown fasciae on anterior cross-vein; calypter wholly brown; plumula golden, halter orange, capitulum orange. Legs ( Fig. 26C ): All femora black, except yellow apically; mesofemur with long black hairs on posterior edge; pro- and mesotibiae yellow; metatibia dark with basal 1/3 yellow; first two tarsal segments yellow, remaining segments brown or blackish; metatarsus elongate, but not thickened. Abdomen ( Fig. 26B ): Black or bluish-black, shining, subopaque, 1 st tergum and anterior angles of following terga shining metallic; sterna black, yellow pilose; male genitalia: surstylus in lateral view ( Fig. 27A ) with dorsal and ventral margins approximately of the same width in the whole length, shorter than broad; hypandrium in ventral view ( Fig. 27C ) narrowed laterally towards the apex; aedeagal lobe in ventral view ( Fig. 27C ) circular, apex rounded.

FEMALE ( Figs 26D–F ). Similar to male except for usual sexual dimorphism and differing in the frontal triangle with an opaque black cross, a dorsal band composed of two coalescent oval spots. Face highly polished, pollen white and confined to a narrow vitta on each side from the antennae, reaching the oral margin, connecting by a broader vitta to the eye and thence along the eye to a triangle opposite lowest depression of face, then connecting with white triangles on lower front; the pile of face short and white. Frontal triangle brownish opaque anterior to the ocellar triangle, bordered dorsally by a very narrow whitish pollinose band; white pollinose band across depression not interrupted, ground color bluish. Abdomen with large opaque or subopaque triangular maculae on 2 nd tergum.

Taxonomic notes. Argentinomyia crenulata can be easily differentiated from A. rugosonasa and A. sagoti sp. nov. by the presence of seven or eight narrow, shallow, transverse grooves above the tubercle and sides of the face with a thin white line of pollen; antennae elongate, scape longer than pedicel and basoflagellomere, pedicel and basoflagellomere about equal in length ( Figs 26A, C , D-F); wings with two short medial transverse brown fasciae on anterior cross-vein ( Figs 26 B-C, E-F); metafemur and protibia black, black pilose ( Figs 26A, C , D-F); abdominal maculae metallic ( Figs 26B, E ). In A. sagoti sp. nov. the face with four or more distinct transverse grooves above the tubercle; antenna short ( Figs 71A, C , D-F); wing lightly brown pigmented anteriorly ( Figs 71 B-C, E-F); protibia yellow on basal 1/3; metafemur and tibia yellow on apically 1/3 ( Figs 71A, C , D-F); 2 nd to 4 th terga without maculae ( Figs 71B, E ). In A. rugosonasa , the face with at least six or seven transversal grooves. Antennae elongate, scape and pedicel a little longer than basoflagellomere ( Figs 69A, C , D-F); wings hyaline ( Figs 69 B-C, E-F); protibia reddish to brownish-yellow; metafemur black or dark brown ( Figs 69A, C , D-F); abdomen opaque black, with metallic maculae, more shining alongside and broadly on anterior corners of 3 rd and 4 th terga ( Figs 69B, E ). Based on males, A. crenulata differs from A. rugosonasa and A. sagoti sp. nov. in having the surstylus in lateral view ( Fig. 27A ) with dorsal and ventral margins approximately of the same width in the whole length [versus surstylus triangular-like in A. rugosonasa ( Fig. 70A ); versus surstylus with dorsal margin slightly concave and ventral margin slightly convex in A. sagoti sp. nov. ( Fig. 72A )] (see “differential diagnosis” under each species or key).

Remarks. We agree with Fluke (1945) who pointed out that, A. crenulata has seven or eight transverse depressions above the tubercle, instead of only three or four transversal grooves as was mentioned by Williston in his description.

Melanostoma crenulatum was described by Williston, 1891: 12, based on specimens collected in Mexico, Guerrero, Xucumanatlan, 7000ft and Omiltemi, 8000ft. Fifteen specimens are deposited in the BMNH, AMNH and USNM labelled as “ Syntype ” and “Cotype”. To avoid the assumption of the Holotype and following the recommendations of the International Commission on Zoology, one male specimen in good condition from the BMNH, labelled “ Syntype ” / “ Melanostoma crenulatum / Williston, 1891 / Mexico. Guerrero, Xucumanatlan, 7000ft and Omiltemi, 8000ft ” is hereby designated as the Lectotype. The remaining syntypes in the AMNH, BMNH and USNM are designated as Paralectotypes to ensure consistent interpretation of this name.

Comments. The Holotype specimen of M. crenulatus is currently in the AMNH. Photos are available on their website AMNH: https://sci-web-001.amnh.org/imulive/iz.html?#details=ecatalogue. 10022086.

Biology. Label data and field observations suggest that A. crenulata visits flowers of Pentacalia trianae (Asteraceae) and Clusia cf. brachycarpa (Clusiaceae) .

Geographical range. Argentinomyia crenulata (n= 42) is distributed in Bolivia * (La Paz), Colombia * (Antioquia, Valle del Cauca), Costa Rica * (Cartago, Guanacaste, Monteverde, San José, Puntarenas), Guatemala * (Cuabrican, Suchitepequez Patulul ) Mexico (Guerrero), Nicaragua * (Matagalpa) and Perú * (Huanuco) ( Fig. 91C ). The species is widely distributed at middle and high altitudes (1200–3000 m) in the following domains and provinces: Mesoamerican (1100–2438 m) : Pacific Lowlands (1900–2438 m), Puntarenas-Chiriquí (1200–1420 m); Northern Andes (1900–3000 m) : Cauca (1900 m), Magdalena (3000 m); Central Andes: Rondônia (1100 m) .

Non-type material examined. BOLIVIA. La Paz, Alto Rio Bendi, South Rio Inicua , -15.162447, -67.865439, 1100 m, 15-18.i.1976, L.E. Peña (1♁, 4♀, AMNH) . COLOMBIA. Antioquia, Betania, Vereda La Oculta , 5.736143, -76.028237, 1700-2100 m, 8.viii.1990, Forest, Leg O. Ortega, Net (1♁, Coll. O. Ortega) ; Antioquia, Bello, San Félix , Las Baldías, 6,330 58, -75,645620, 3150 m, Páramo , Net , 16.vii.2015, A.L. Montoya (1♁, CEUA 93076 ) ; Belmira, Páramo Santa Inés, Cabaña Cabildo Verde , El Morro-Alto de La Gallina , 6,632 639, -75,645267, 3200 m, Páramo , Net , 4-14.ii.2017, A. L. Montoya; C. Rodríguez; J. D. Carmona (1♁, CEUA 95444 ) ; Net , 21- 30.vi- 5.iv.2017, C. Rodríguez; J. P. Carmona (1♀, CEUA 98117 ) ; ex Pentacalia trianae, Net , 25.iii-5.iv.2017, A. L. Montoya; C. Rodríguez; J. D. Carmona (1♀, CEUA 97931 ) ; 6,634 233, -75,658654, 3020 m, Forest, Net , 21- 30.vi- 5.iv.2017, C. Rodríguez; J. P. Carmona (3♁, CEUA 98123 ) ; 4-14.xii.2016, A. L. Montoya; J. Torres; J. P. Carmona (1♁, 1♀, CEUA 95111 ) ; Belmira, Páramo Santa Inés, Vereda Río Arriba , Sector Laguna de Sabanas , 6,640 931, -75,665335, 2950 m, Forest , Malaise , 16-27.ix.2017, A. L. Montoya; Y. Cardona (1♁, CEUA 103259 ) ; …, Net , 16- 27.ix.2017, A. L. Montoya; Y. Cardona (1♁, CEUA 103270 ) ; …, 6,645 901, -75,670441, 3200 m, Páramo, Malaise , 4-14.ii.2017, A. L. Montoya; C. Rodríguez; J. D. Carmona (1♀, CEUA 95472 ) ; …, ex Clusia cf. brachycarpa, Net , 4-14.ii.2017, A. L. Montoya; C. Rodríguez; J. D. Carmona (3♁, CEUA 95317 ) ; Valle del Cauca, 6 miles, W. Cali Valle, 3,466 968, -76,61496, 1630 m, 20.iii.1955, E. I. Schillinger and E. S. Ross (2♁, CAS) . COSTA RICA. Cartago, Tapanti, Quebrada Segunda, Orilla del Rio Grande de Orosi , 9.796431, -83.928767, 1000–1500 m, 18- 19.ii.1997, M. Segura (3♁, 1♀, Catalogue number 45297, 6365, 45358); Rio Grande de Orosi , desde Administración hasta Sendero La Pava , 9,797 784, -83,925756, 1150–1600 m, 10.i.1989, R. Delgado (1♁, INBIO CRI 002363749 ) ; Guanacaste, Estación Cacao, Lado sur del Volcán Cacao , 10.926655, -85.468226, 1000–1400 m, vi.1990, InBio , III curso Parataxomy (4♁, 1♀, INBIO CRI 002 47985,..0318,..3446 &..9982); Monteverde , 10.308668, -84.812366, 1420 m, 20-25.viii.1991, D.M. Wood (1♀, CNC DIPTERA 112227 ); …, (2♁, INBIO CRI 002568656 , 002568658 ) ; San José, Estación Santa Elena Sendero La Bota 3, 5 km al SE del Cerro Chucuyo , 10,343 385, -84,793508, 1690 m, 18.iii.1997, M. Segura (1♀, INBIO CRI 002535940 ) . GUATEMALA. Cuabrican, 15,086 864, -91,605864, 2999 m, 13.vi.2006, #6, José Monzón (1♁, Colección J. Monzón); Suchitepequez Patulul Finca Tarrales, Volcán Atitian , 14,487 269, -91,150858, 770 m, 8.v.2005, José Monzon (1♀, Colección J. Monzon) . NICARAGUA. Matagalpa, Selva Negra Mountain Resort lower forest, 12,996 416, -85,908733, 700–1000 m, 20.vi.2007, N.E. Woodley (1♀, USNM ENT 0143745 ) . PERÚ. Huanuco, 10 mi SW Las Palmas , -9,385742, -76,004373, 1000 m, 2.6 iv.1954, E. I. Schillinger and E. S. Ross (1♁, CAS) .

Figures

FIGURE 3. Detail of metasternum development: A. Metasternum highly reduced in Melanostoma; B. Metasternum entire, not reduced in Argentinomyia. Abbreviations: Mtst: Metasternum; Cx 3: Coxae 3.

FIGURE 26. Argentinomyia crenulata (Williston, 1891), male (INBio CRI 002568658): A. Head, frontal view; B. Dorsal view; C. Lateral view. Female (INBio CRI 000409982): D. Head, frontal view; E. Dorsal view; F. Lateral view. Scale bars: 5 mm.

FIGURE 27. Argentinomyia crenulata (Williston, 1891), 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 70. Argentinomyia rugosonasa (Williston, 1891), male genitalia. A. Whole genitalia, lateral view; B. Epandrium, dorsal view; C. Hypandrium, ventral view. Scale bars: 1 mm. D. Natural habitus of a male specimen in El Calvario, Toluca, México (iNaturalist catalogue number 17119892; https://www.inaturalist.org/observations/17119892); E. Natural habitus of a female specimen in Toluca de Lerdo, México (iNaturalist catalogue number 8506135; https://www.inaturalist.org/ observations/8506135). Photos taken by ©Juan Carlos García Morales.

FIGURE 71. Argentinomyia sagoti sp. nov., male Holotype (ECOSCE): A. Head, frontal view; B. Dorsal view; C. Lateral view. Female (ECOSCE 24470): D. Head, frontal view; E. Dorsal view; F. Lateral view. Scale bars: 5 mm.

FIGURE 72. Argentinomyia sagoti sp. nov., male Holotype, genitalia. A. Whole genitalia, lateral view; B. Epandrium, dorsal view; C. Hypandrium, ventral view. Scale bars: 1 mm.

FIGURE 91. Geographical distribution of Argentinomyia species in Central and South America.