On the identity of Lepidodexia (Orosarcophaga) ornata (Townsend, 1927) (Diptera: Sarcophagidae) and a new generic synonym

The revision of the sarcophagid species Lepidodexia (Orosarcophaga) ornata (Townsend, 1927) reveals its identity and a generic synonym. The male terminalia of this species was studied in detail for the first time and revealed its congeneric affinities with Oxyvinia Dodge, 1966. Consequently, the generic status of Orosarcophaga Townsend, 1927 was revalidated, including Oxyvinia Dodge, 1966 as its junior synonym, and O. ornata was corroborated as a valid species and name. Moreover, we provide an updated generic diagnosis of Orosarcophaga, a list of the eleven species of the genus with their distribution, and a detailed diagnosis of O. ornata.


INTRODUCTION
The genus Lepidodexia sensu Pape (1996) is composed of 32 subgenera, of which 11 are monotypic (e.g., Orosarcophaga), and it is recognized mainly by some features present in the male terminalia (Pape, 1996;Buenaventura & Pape, 2018). For some Lepidodexia species, this structure was never represented in the literature, leading to some doubts about the generic placement of such taxa, as is the case of Lepidodexia (Orosarcophaga) ornata.
The species currently recognized as Lepidodexia (Orosarcophaga) ornata (Townsend, 1927) was originally described in the monotypic genus Orosarcophaga Townsend, 1927. Later, this genus was considered a junior synonym of Lepidodexia by Pape (1996), who gave a subgeneric status to Orosarcophaga, keeping only its type species. The same action was proposed by Pape (1996) for Orodexia Townsend, 1927 andOrobrachycoma Townsend, 1927, which resulted in the secondary homonym of Lepidodexia (Orosarcophaga) ornata (Townsend, 1927), Lepidodexia (Orodexia) ornata (Townsend, 1927), and Lepidodexia (Orosarcophaga) ornata (Townsend, 1927). Also, Pape (1996) did not explain his criteria for this taxonomic arrangement but stressed that no action was taken to correct the homonymy between Orodexia and Orosarcophaga due to the need for a revision of Lepidodexia [s.l.], with the decision being made then by the first reviser. Townsend (1927: 342) described Orosarcophaga ornata based on one male and one female specimens, showing only general coloration characteristics. Later, Townsend (1938: 47) presented a more complete description of the genus and species and designated the male specimen as a "holotype" [correctly, it should be lectotype], but the author did not provide any aspect of the terminalia or illustrations. This type specimen had never been studied since. Therefore, the male terminalia of the lectotype of O. ornata was studied in detail for the first time herein, along with other specimens recently collected in Brazil.

MATERIAL AND METHODS
The lectotype of Orosarcophaga ornata housed at the National Museum of Natural History (USNM), Smithsonian Institution, Washington, was examined along with two additional specimens of the Museu Nacional (MNRJ), Universidade Federal do Rio de Janeiro, Rio de Janeiro. For morphological comparisons, seven specimens of six species of Oxyvinia and two specimens of Hallina retusa (Hall, 1933) from the MNRJ were examined, as well ISSN On-Line: 1807-0205 ISSN Printed: 0031-1049 ISNI: 0000-0004-0384-1825 as literature data on all known Oxyvinia species. We provide additional information on the examined material between brackets.
Pictures were taken with the software LAS coupled to a stereomicroscope and assembled in software Helicon Focus 6. After the abdomen removal, the male terminalia were treated with 10% KOH at 40℃ for 25 min, then rinsed in 1% acetic acid and transferred to a microvial with glycerin. Drawings were made using a camara lucida coupled to a microscope, then edited using Adobe Illustrator CS software. The external morphology nomenclature follows Cumming & Wood (2017) and, for the distiphallus elements, Mello-Patiu & Pape (2000), except "median stylus" and "paraphallus", which are under the concepts by Giroux et al. (2010) and Whitmore et al. (2013), respectively.

RESULTS
After a detailed morphological study of Orosarcophaga ornata, it is clear to state that this species indeed shares diagnostic features with members of the genus Oxyvinia Dodge, 1966, as those elucidated by Dodge (1966), Lopes (1982), Pape (1996), and Buenaventura & Pape (2018). In consequence, we revalidate Orosarcophaga as a valid generic name. Moreover, O. ornata does not resemble any other species currently allocated in Oxyvinia, and it is corroborated as a valid species as well.
Ten species have been recognized in Oxyvinia, but Pape (1996) included eleven species in his catalog due to the inclusion of O. retusa (Hall, 1933). In the work by Pape (1996), this species was cataloged twice, as both Hallina (page 234) and Oxyvinia (page 272). Lopes (1975) reviewed the species described by David Hall from Panama and furnished its redescription as Hallina retusa. Our examination of the specimens deposited at the MNRJ also showed that H. retusa does not really resemble the Oxyvinia species, and we did not include it in our checklist.
Below, we provide an updated generic diagnosis of Orosarcophaga, including features of the male terminalia, a list of the eleven species of the genus with their distribution, and a detailed diagnosis of O. ornata.

Genus Orosarcophaga Townsend
Orosarcophaga Townsend, 1927: 231 2B; arrow) covered by setae or spines; reddish or yellowish-brown male terminalia; apically curved pregonite relative to the base in profile; phallus with a distinct hinge between basi-and distiphallus; paraphallus bent in its proximal third; well-developed vesica with proximal section (vesical arm-shaped lever sensu Buenaventura & Pape, 2018) covering the remaining parts and distal section bifid; juxta attached to the paraphallus with a smooth surface, often with a sclerotized distal portion and a membranous proximal portion; median stylus with a basal pair of elongated processes (capitis sensu Buenaventura & Pape, 2018); robust lateral styli with an elongated base that extends laterally towards the paraphallus wall.
Comments: No females were available; therefore, they were not included in the generic diagnosis.
Head (Figs. 1A-B): Parafacial and fronto-orbital plates with intense golden pruinosity; parafacial plate with a row of setulae close to the eye; frons about 0.30x head width at ocellar triangle level; entirely blackish frontal vitta; rows of parallel frontal setae except two slightly divergent anteriormost, 9-10 well-developed frontal setae reaching pedicel apex level; reclinate orbital seta present, proclinate orbital setae absent; outer vertical setae 0.3x inner vertical; black ocellar triangle, ocellar setae as developed as frontals; postocular area with yellowish-gray pruinosity; gena with golden pruinosity and black setae; black postgena with slightly silvery pruinosity, black setae and some few whitish setae close to occiput; face with golden pruinosity; black facial ridge with short setulae in the inferior half; black antenna, first flagellomere with gray pruinosity and about 2x longer than pedicel; arista long plumose on basal 2/3; blackish palpus.
Abdomen 2B): Black with silvery-gray pruinosity; T3 with 1 lateral marginal and no median marginal setae; T4 with 3 lateral marginal and 1 median marginal setae; T5 with a complete row of marginals (ca. 20); rectangular ST2-4, ST2-3 with numerous long hair-like pale setae and some black ones; ST3-4 with a patch of black setae on the middle of the posterior margin; blackish ST5 with a cushion-like elongated process in the inner margins, covered by spinous setae (Fig. 2B).

Remarks:
The lectotype was on loan at the MNRJ and, unfortunately, it was lost during the fire which destroyed the MNRJ Entomological Collection (Duarte, 2019). We observed that there are individual differences in the number of teeth in the juxtal lateral dentation among the specimens examined (2 or 3 teeth on each side of the median teeth pair).

DISCUSSION
Despite the presence of setae on the postalar wall, Orosarcophaga ornata does not possess the vesica C-shaped with a convex distal section, juxta angled relative to the phallic tube, developed bacilliform sclerite, nor a spinose lobe above the vesica, all diagnostic characteristics of the genus Lepidodexia (Pape, 1996;Buenaventura & Pape, 2018;Riccardi & Mello-Patiu, 2020). Also, the result of an ongoing morphological phylogeny of Lepidodexia shows O. ornata nested with O. xanthophora, separated from all the remaining species of Lepidodexia (Riccardi & Mello-Patiu, 2020). In the phylogenetic hypothesis of Sarcophaginae proposed by Buenaventura & Pape (2018), three species of the former Oxyvinia were nested with Dexosarcophaga species; however, Orosarcophaga ornata was not included in the taxonomic sample. Riccardi & Mello-Patiu (2020) nested Orosarcophaga with Oxysarcodexia Townsend instead of Dexosarcophaga Townsend, but the taxon sampling of Sarcophaginae except Lepidodexia was limited. Despite the differences aforementioned, both phylogenies indicate that Orosarcophaga (including Oxyvinia) does not belong to Lepidodexia.
The male terminalia elements of sarcophagids are often the most reliable morphological features to establish phylogenetic relationships (Giroux et al., 2010;Buenaventura & Pape, 2018). In this sense, the most conspicuous characteristic gathering the members of the former Oxyvinia into Orosarcophaga is the median stylus with a peculiar basal pair of elongated processes, which seems to be a unique feature within Sarcophaginae ( Fig. 2D; arrow). Additionally, the type species of Orosarcophaga also share with O. vittata and O. xanthophora the presence of a dentate margin on the apex of juxta. This evidence, along with the remaining features discussed above, supports our taxonomic decision.