Zelia Robineau-Desvoidy, 1830

Dios, Rodrigo de Vilhena Perez & Santis, Marcelo Domingos de, 2019, A new synonym for Zelia Robineau-Desvoidy, 1830 (Diptera, Tachinidae), the genus Opsozelia Townsend, 1919, with the description of three new species, ZooKeys 880, pp. 113-133 : 115-117

Genus Zelia Robineau-Desvoidy, 1830

Zelia Robineau-Desvoidy, 1830: 314. Type species: Zelia rostrata Robineau-Desvoidy, 1830 (= Dexia vertebrata Say, 1829), by subsequent designation of Coquillett, 1910: 621.

Leptoda van der Wulp, 1885: 196. Type species: Dexia gracilis Wiedemann, 1830 (= Dexia vertebrata Say, 1829), by subsequent designation of van der Wulp, 1891: 250.

Melaleuca van der Wulp, 1891: 213. Type species: Melaleuca spectabilis van der Wulp, by subsequent monotypy of van der Wulp, 1891: 247.

Metadexia Coquillett, 1899: 220. Type species: Metadexia tricolor Coquillett, 1899, by monotypy.

Euzelia Townsend, 1915: 23. Type species: Zelia wildermuthii Walton, 1914, by original designation.

Minthozelia Townsend, 1919: 556. Type species: Minthozelia montana Townsend, 1919, by original designation.

Opsozelia Townsend, 1919: 557. Type species: Opsozelia discalis Townsend, 1919 (= Musca lateralis Fabricius, 1805), by original designation, syn. nov.

Notes.

The genus Zelia is a group with 19 valid species at present. This study began as a revision of the previously valid genus Opsozelia , but later it was recognized as a synonym of Zelia. Since the original intent of this study was not to revise Zelia , we were not able to examine all Zelia species. Therefore, we cannot provide a full description for the genus. Instead, we provide a small diagnosis for the genus, as well as some features for the Dexiini , modifying what was stated by Thompson (1963) and Mesnil (1980). The species of Zelia with at least two discal setae on abdominal tergites III and IV (i.e., members of the Z. discalis species group), are then revised.

Diagnosis.

Zelia shares with Dexiini the following characters that, simultaneously, differs from other Tachinidae : compound eye bare (except for Callotroxis Aldrich, 1929 and Huascarodexia Townsend, 1919). Front narrow and without orbital setae in male, broad and with one proclinate orbital seta in female. Lunula bare. Frontal setae, forwardly directed or crossed, anteriorly reaching external angle of lunula, or slightly in front of it, but never descending to parafacial (except in Psecacera Bigot, 1880, Morphodexia Townsend, 1931 and Dasyuromyia Bigot, 1885). Facial carina absent. Antenna short, inserted at level or below half of compound eye height, thickened only at its base, often pubescent or plumose. Thorax with scutellum with decussate (rarely parallel) apical setae, normally without lateral setae. Abdominal sternites usually completely covered by ventrolateral margins of corresponding tergites.

Zelia differs from other Dexiini genera by the following combination of characters: Head silver pruinose (golden pruinose in Myiomima Brauer & Bergenstamm, 1889). Pedicel with one long seta and various setulae on its surface (in Neozelia Guimarães, 1975 with a tuft of long setulae). Postpedicel long, compressed laterally. Arista long plumose (bare in Psecacera ). Facial carina absent (e.g., present in Platyrrhinodexia Townsend, 1927). Haustellum short, ca. 0.5 × the head height (e.g., two or three times in Prosenoides Brauer & Bergenstamm, 1891). Thorax with proepisternum and prosternum bare (e.g., setulose in Tromodesiana Townsend, 1931). Intrapostalar seta absent. Scutellum with just regular setae (e.g., various upturned setae in Tropidopsiomorpha Townsend, 1927). Wing hyaline (smoky in in Yahuarmayoia Townsend, 1927; with maculae in Scotiptera Macquart, 1835). Costal spine undeveloped. Abdomen strongly pointed apically, especially in male (in Yahuarmayoia and Z. discalis species group is broad, excluding Z. formosa sp. nov.). Male abdomen somewhat elongate (not elongate in Ophirodexia Townsend, 1911). Abdominal tergites with just one row of setae (e.g., in Hystrichodexia Röder, 1886, two or three rows of discal setae). Tergite IV with three to five discals or without discals (e.g., with discal setae in sytergite I+II to V in Ptilodexia ).

Justification for the synonymy of Opsozelia with Zelia and the Z. discalis group of species with at least two discal setae on tergites III and IV:

All of the examined species of the Z. discalis species group are similar to Zelia species, including the terminalia. These species do not present any outstanding morphological features that justify a separate genus. However, considering the difficulty in identifying the Neotropical Dexiini and Zelia species, we keep maintain species in their own species group for identification purposes. These species are easily recognized among other Zelia by the presence of at least two discal setae on abdominal tergites III and IV (other Zelia species without discal setae on these tergites).

Description of the Zelia discalis species group

Male holoptic and female dichoptic. Compound eye bare. Frontal vitta and ocellar triangle dark brown. Head light yellow to tawny, covered entirely with silver pruinosity. Minute proclinate setae on fronto-orbital plate. Parafacial bare. Ocellar setae proclinate and well differentiated from the adjacent setae; postocellar setae proclinate. Inner and outer vertical setae subparallel and convergent. No facial carina. Genal dilation with pale pruinosity and covered with black setulae. Facial ridge with small setulae near vibrissal insertion. Antenna inserted below middle of compound eye. Arista densely plumose. Strong and convergent vibrissae; four or five developed subvibrissal setae. Palpus cylindrical and a little clavate. Thorax brown to dark brown with silver or light golden pruinosity. Prescutum with four dark vittae, the two inner vittae thinner than the outer vittae. Prosternum and proepisternum bare. Notopleuron with two equal-sized setae. Two proepimeral setae. Two proepisternal setae. Three katepisternal setae, the lower one weaker. Postalar callus with two large and one smaller setae. Anepimeron with a single long seta. Anatergite bare. Katepimeron with setulae anteriorly. Costal spine absent. Vein M1 ending at wing margin close to tip. Abdomen conical, basally large and rounded, tapering to tip. Mid-dorsal depression on syntergite I+II reaching the posterior margin. Syntergite I+II and tergite III with one pair of median marginal setae. Tergite III and IV with 2-4 pairs of discal setae. Tergite IV with one row of median marginal setae and approximately ten discal seta decreasing in size anteriorly. Tergite V with one row each of marginal and discal setae. Sternites hidden. Male terminalia with cerci separated and pointed, larger basally. Surstylus broad, and usually rounded at tip, sometimes slightly pointed. Pregonite and postgonite fused as curved elongate structure, without a distinct separation; pregonite connected basally to the hypandrium by a membrane (sometimes thin, almost sclerotized). Epiphallus present, fused with basiphallus. Basiphallus varying in size. Distiphallus with extension of dorsal sclerite varying in size; dorsal sclerite ventrally serrulated; granular zone present, varying in size.