Taxonomic revision of the Neotropical genus Argentinomyia Lynch-Arribálzaga, 1891 (Diptera: Syrphidae), with description of 16 new species Author Montoya, Augusto L. 0000-0003-3307-034X aleon.montoya@udea.edu.co Author Wolff, Marta 0000-0002-3389-7083 martha.wolff@udea.edu.co text Zootaxa 2023 2023-02-03 5234 1 1 157 http://dx.doi.org/10.11646/zootaxa.5234.1.1 journal article 53225 10.11646/zootaxa.5234.1.1 be77753c-0c7a-4f90-a020-f23b778d06d0 1175-5326 7609993 A540F250-BDE2-43F7-83A1-DA261F914B41 Argentinomyia scitula ( Williston, 1888 ) ( Fig. 73 ) Melanostoma scitulum Williston, 1888: 264 . Type locality: BRAZIL . Mato Grosso , Chapada. SYNTYPE 2 Male AMNH (Examined). Refs.: Fluke, 1945: 7 (redesc.) 29 ( Fig. 43 , male abdomen, Fig. 54 , wing) Rhysops scitulum . Williston, 1907: 2 Rhysops scitula . Curran, 1937: 2 (key) Rhysops scitula . Fluke, 1945: 7 Rhysops scitulus . Thompson et al. 1976: 44 FIGURE 73. Argentinomyia scitula ( Williston, 1888 ) , male Holotype, AMNH (Headless). Type material. HOLOTYPE . Adult male, BRAZIL . Mato Grosso , Chapada , 15°27’43.51”S , 55°44’54.20”O , 716 m ( AMNH ). Length. Body, 7.2–8.0mm; Wings, 5.7–6.4mm . Diagnosis. Argentinomyia scitula is similar to Argentinomyia longicornis differing by the following combination characters: Basoflagellomere as long as the scape and pedicel together; wings with two short, transverse maculae in front on median half, microtrichose; protarsus are wholly yellow; abdomen with a basal pair of elongate yellow maculae on 3 rd tergum reaching the apical 1/3, a similar smaller pair on 4 th tergum separated from the base of tergum and occupying 1/2 its length. Redescription. MALE. Head (Adapted from Williston 1888 and Fluke 1945 ). Sides of the face with a slender vitta and spot of pollen, not punctulate. Antennae brownish, orange ventrally, less elongated, the three segments of nearly equal length, basoflagellomere not twice as long as wide. Thorax: Black, mesonotum shining, with two faint whitish-pollinose vittae on anterior half, yellow pilose, the side brownish pollinose, pile brownish. Pleura shining black with a light coating of white to brownish pollen, mesopleura with brownish metallic reflections, yellow pilose. Scutellum shining, slightly rugose on apical 1/2, pile long and yellow, fringe long and yellow. Wing ( Fig. 73 ): Hyaline, stigma light brownish, elongate, anterior cross-vein (r-m) clouding; calypter wholly dark brown; plumula light brown; halter yellowish-red, capitulum slightly brownish. Legs: Yellow, pro- and mesotibiae yellow; pro- and mesofemora dark brown, yellow at the anterior 1/4, femur narrowly yellow at the base; pro- and metafemora only pale brown on basal 1/2 but may be quite dark on fully matured specimens. Abdomen ( Fig. 73 ): narrow, of nearly equal width throughout; with a basal pair of elongate yellow maculae on 3 rd tergum reaching the apical 1/3, a similar smaller pair on 4 th tergum separated from the base of tergum and occupying 1/2 its length. Remarks. Fluke (1945) was unable to recognize A. scitula (Williston) among the numerous specimens he studied from southern Brazil . Fluke reviewed a male from the AMNH ( Fig. 73 ) pointing out that the opacity of the anterior transverse vein (r-m) is quite characteristic, but it is not entirely reliable as other species such as A. crenulata also have a slightly brown macula along this vein. These characteristics were verified and corroborated during the visit to the AMNH. The Holotype in the AMNH is a specimen collected in Chapada , Rio Grande do Sul , Brazil . Apparently , A. scitula could be a valid species, but as the Holotype is a headless, teneral and undissected male, there were nonadditional specimens found, although extensive material from Brazil was examined, therefore, the identity of the species remains doubtful and a more in-depth morphological analysis will be necessary to clear up its validity . Comments. The Holotype specimen of M. scitulum is currently in the AMNH . Photos are available on their website AMNH : https://sci-web-001.amnh.org/imulive/iz.html?#details=ecatalogue.10020982. Geographical range. Argentinomyia scitula is distributed in Brazil ( Rio Grande do Sul ).