Revision of the Neotropical Obscure Genus Ebenia Macquart 1846 (Diptera, Tachinidae, Dufouriini)

The Neotropical genus Ebenia Macquart, 1846, is a member of the tribe Dufouriini (Dexiinae), and before the current work, comprised four species, viz. E. claripennis Macquart 1846, E. fumata (Wulp, 1891), E. neofumata Santis & Nihei, 2022 and E. trichopoda (Wulp, 1891). The present taxonomic revision results in a new generic synonymy: Comyops Wulp, 1891 syn. nov. of Ebenia. The following two new combinations result from this act: E. nigripennis (Wulp, 1891) comb. nov. and E. striaticollis (Wulp, 1891) comb. nov. both originally described in Comyops. In addition, the species originally described as Homodexia spinosa Bigot, 1889 is moved from its current placement in Thelairodes Wulp, 1891 to Ebenia as Ebenia spinosa (Bigot, 1889) comb. nov. A new specific synonymy is proposed for this last species: Morinia trichopoda Wulp, 1891, previously treated as a valid species of Ebenia, becomes a junior synonym of E. spinosa. All valid species are redescribed and photographed with the first description and illustration of the male terminalia for E. claripennis, E. neofumata and E. nigripennis and female terminalia for E. spinosa. Additionally, lectotype fixations are made for E. nigripennis and M. trichopoda. Finally, an updated diagnosis for the genus Ebenia and a key to the six known species are provided.


Introduction
The tachinid tribe Dufouriini is placed in Dexiinae and is currently known from all regions of the world (Santis & Nihei 2022).This tribe is composed of five genera: Chetoptilia Rondani, 1862; Comyops Wulp 1891; Dufouria Robineau-Desvoidy, 1830; Ebenia Macquart 1846a, b and Rondania Robineau-Desvoidy, 1850.Of those genera, only Comyops and Ebenia are from the Neotropical region.Although the overall trend of tachinids from this region is being poorly known (see, e.g., Santis 2021Santis , 2022)), both genera are an exception due to the redescriptions of some of its species amde by Thompson (1963).After the works of Townsend (1939), which placed Comyops and Ebenia in the former tribe Ebeniini together with taxa currently in Palpostomatini (Tachininae) and Voriini (Dexiinae), Thompson (1963) was the first to hypothesize the possible close relationship between these genera.Additionally, Thompson (1963) also noted that the male genitalia of Comyopsis resemble those of Dufouria nigrita (Fallén, 1810), as figured by Verbeke (1962: Fig. 1 of plate X).
The views of Thompson (1963) were confirmed by the molecular phylogeny of Stireman et al. (2019) that recovered an undetermined species of Ebenia in a clade that clustered it with genera such as Dufouria and Rondania, both dufouriines.In addition, Stireman et al. (2019) Dufouriini was recovered as paraphyletic.Thus, the precise limits of Dufouriini and the relationships among these taxa remained unclear.These issues were clarified by the morphological phylogeny of Dufouriini by Santis & Nihei (2022), in which this tribe was recovered as monophyletic and conclusively recovered the following phylogenetic relationships: (Rondania (Chetoptilia (Dufouria (Ebenia + Comyops).Even though the phylogenetic placement of Ebenia is well known, the taxonomic delimitation of this genus is far from clear, with its current species E. claripennis Macquart 1846a, b, E. fumata (Wulp 1891), E. neofumata Santis & Nihei 2022 and E. trichopoda (Wulp 1891) not appearing in any key or comparative analysis.In consonance with that, the three host records for this genus are all Chrysomelidae (Coleoptera) based on undetermined species: Janzen & Hallwachs (2005) for Sceloenopla scherzeri (Baly, 1858), Cuignet et al. (2008) for Chelymorpha alternans Boheman, 1854 and Spaethiella marginata (Champion, 1893); similarly, the phylogeny of Stireman et al. (2019) could not determine the species of Ebenia sampled in their work.Interestingly, a peculiarity of the members of this tribe is their hosts being adult beetles and their female terminalia being modified into different forms (Santis & Nihei 2022) to achieve the introduction of their larvae into those beetles, and particularly, Ebenia females that bears the sternite 8 as a cone-shaped structure.
The aim of this study is to provide a comprehensive revision of the species of genus Ebenia, and to clarify its generic and specific limits.All species were redescribed and photographed, in addition to the first description and illustration of the male terminalia for E. claripennis, E. neofumata and E. nigripennis and female terminalia for E. spinosa.Additionally, lectotype fixations are made for E. nigripennis and M. trichopoda.

Material and Methods
The examined material from each institution, as well as the mode of access of the material (loan, photos, visit), are indicated as follows: ARC -Arthropod Research Collection, Michigan State University, Michigan, USA -loan; MNCR, Museo Nacional de Costa Rica [formerly Instituto Nacional de Biodiversidad -INBio], Santo Domingo de Heredia, Costa Rica -loan; MNRJ, Museu Nacional, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil -visit and loan; MZSP, Museu de Zoologia da Universidade de São Paulo, São Paulo, Brazil -visit and loan; NHMUK, Natural History Museum, London, UK -visit; USNM, Smithsonian National Museum of Natural History, Washington, D.C., USA -photos.
Additional acronymous in the text: OMNH -Oxford University Museum of Natural History, Oxford, UK.The label data are presented within quotation marks for each label, with forward slashes indicating line breaks and semicolons separating different labels.Morphological terminology follows Cumming & Wood (2017).
Photographs of the pinned specimens were taken using a Canon EOS 5DS R digital camera for the material deposited at NHMUK, a Leica MC170 HD digital camera attached to a Leica MZ16 stereomicroscope for the MNRJ and MZSP material, and an Olympus E-M5 digital camera for the material deposited at USNM.The images were subsequently stacked (merging different focal planes into one image) with the software Helicon Focus 7.5.8 and edited in Adobe Photoshop CC 2019.Illustrations were made using a camera lucida attached to a Leica MZ16 stereomicroscope, and edited and arranged in Adobe Illustrator CC 2019.To digest tissues and clear structures, the last abdominal segments were put into a glass tube containing a 10% KOH solution and heated in boiling water for 5 min, neutralized in a 5% acetic acid solution, and rinsed in distilled water.After examination, the dissected parts were placed in glycerin inside a plastic microvial pinned with the source specimen.
Distribution.Mexico (Veracruz, Tabasco, Guerrero), Costa Rica (Guanacaste, Cartago), Nicaragua, Trinidad & Tobago and Brazil (Rio de Janeiro).In addition, based on the records of the CNC online database, some undetermined specimens of Ebenia further expands the distribution of this genus by the following countries: Venezuela (Aragua), Colombia (Valle Rio Anchicaya), Ecuador (Napo) and Bolivia (Cochabamba).
Remarks.Guimarães 1971: 216) listed Hylemyia probata Walker, 1861 from Mexico as an unrecognized species of Tachinidae.I examined the holotype of this species in NHMUK and it is in poor condition with only a portion of the thorax remaining.D.M. Wood examined the specimen in 1989 and labeled it as "Ebenia", but I have concluded that a determination to genus, or even to subfamily, is not possible based on the remaining structures of the holotype.

Key to Dufouriini Genera
The dufouriines, as recognized by Santis & Nihei (2022), are difficult to be succinctly characterized as many characters vary among its genera.Usually, dufouriines are small blackish tachinids with males bearing big eyes, almost touching on top, while females have eyes that are widely separated.In addition, females bear specialized terminalia that are particularly adapted to infect adult beetles utilizing different strategies and forms.To further assist the reader, a generalized description of the tribe is given: the head is always without orbital setae in males, parafacial is bare, facial carina absent, antennal axis at or below middle level of eye; lower facial margin not prominent, prementum shorter than head height.Thorax with bare prosternum, with two equalsized notopleural setae, scutellum usually with strong apicals and basals; wing with cell R 5 open, just closed at the wing margin, or long petiolate.Abdomen is ovalate to somewhat cylindrical, chaetotaxy is irregular, with variation in both numbers and strength of setae, it may be absent, with just setulae, as in Rondania dorsalis (Coquillett, 1902) or with numerous strong setae, as in Dufouria chalybeata (Meigen, 1824).
At the NHMUK Diptera collection there is a single female that bears the usual label from Macquart that indicates a type specimen and includes the suffix "n.g., n.sp." after the name ["Ebenia claripennis ♀"] and the additional label of Bigot indicating the specific name and the sex symbol towards the top, the type-locality on the bottom left ["Brésil"] and authority of the species at the bottom right ["Macq."].Although there is a label attached to this specimen that indicates that this is a "Holotype", Macquart did not restrict the name-bearing type to a single specimen and no lectotype fixation has been published subsequently.Thus, the "holotype" in NHMUK is technically a syntype (see Recommendation 73F of the Code (ICZN 1999), "Avoidance of assumption of holotype").
In the interests of nomenclatural stability and to restrict the name to a single specimen, female syntype in NHMUK is herein designated as lectotype of Ebenia claripennis Macquart 1846a, b.
The current combination for this species is Ebenia claripennis Macquart 1846a, b.Diagnosis.Eyes with very small and widely scattered setulae.Fronto-orbital plate dark silver pruinose.Postpedicel entirely dark brown.Facial ridge with setulae only at base.Prosternum with setulae.Thorax with silver pruinosity.Wing hyaline; vein R 4+5 with setulae beyond the cross-vein r-m.Costal spine developed.Abdomen light brown with silvery pruinosity anteriorly on tergites 3 to 5. Male terminalia with surstylus bearing short spines laterally on posterior view.

Type material examined
Redescription of male.
Head (Fig. 1): Vertex about 0.18 × head width in dorsal view.Width of parafacial, measured at distance between inner margin of eye and antennal insertion, 2 × height of gena.Postpedicel about 1.5 × the combined lengths of scape and pedicel.Frontal vitta narrowed dorsally.Eye about 0.8 × the head height.Gena about 0.12 × eye height.Prementum about 0.5 × head height.Labellum developed, about 0.1x as long as prementum.
Abdomen (Fig. 1a, c): Syntergite 1 + 2 with mid-dorsal longitudinal depression extending until ¼ to posterior margin.Syntergite 1 + 2 with at least 4 pairs of lateral marginal setae; tergite 3 with at least 4 pairs of lateral marginal setae and a pair of median marginal seta.
Terminalia (Fig. 2): Sternite 5 with slightly developed lobules, setulose, with basal plate long and slightly curved (Fig. 2a, c); sensilla "trichodea" present on distal portion.Epandrium broad in posterior view, setulose, and closed dorsally.Surstylus somewhat narrow, not fused with epandrium, convex, setulose in posterior view and with eight short spines laterally on frontal view; distally tapered in lateral view.Extension of dorsal sclerite of distiphallus ending in an expanded region.
Female.Differs from male as follows: head with fronto-orbital plate about twice larger as the male, two proclinate and two reclinate orbital setae.Abdomen shorter and broader than male.
First instar larvae.A complete description was given by Thompson (1963: 480), and the reader is referred to that work.
Biology.Parasitoid of Coleoptera larvae.A specimen from MZSP is pinned with a larva of undetermined species of Hispinae (Chrysomelidae) with a puparium of E. claripennis inside it.
Distribution.Mexico (Veracruz, new record), Trinidad & Tobago and Brazil (Rio de Janeiro, new record).Diagnosis.Eyes with very small and widely scattered setulae.Fronto-orbital plate dark silver pruinose.Postpedicel entirely dark brown.Facial ridge with setulae only at base.Prosternum with setulae.Thorax with silver pruinosity.Wing smoky; with vein R 4+5 with setulae about ¼ halfway to crossvein r-m.Costal spine poorly developed.Abdomen light brown with silvery pruinosity anteriorly on tergites 3 to 5.
Redescription of holotype male.
Coloration (Fig. 3a-b, d): Occiput with silver pruinosity.Head with dark silver pruinosity.Scape light brown and pedicel dark brown.Postpedicel dark brown.Arista dark brown, but proximal 1/5 light brown.Palpus yellowish.Labellum light brown, prementum shiny black.Scutum brownish, but presutural region and anterodorsal portion of postsutural region with brownish-silvery pruinosity; presutural region with five brownish-black vittae, the three central ones narrow and the two peripheral ones broad.Scutellum brownish.Wing smoky on apical region.Tegula and basicosta dark brown.Halter yellowish.Posterior spiracle light-brown.Legs brownish.Upper and lower calypters hyaline.Abdomen light brown with anterolateral silver pruinosity on tergites 3 to 5.
Head (Fig. 3a-b, d): Vertex about 0.12 × head width in dorsal view.Width of parafacial, measured at distance between inner margin of eye and antennal insertion, 2 × height of gena.Fronto-orbital plate with setulae throughout its length.Frontal vitta narrowed dorsally.Eye about 0.9 × the head height.Gena about 0.12 × eye height.Prementum about 0.5 × head height.Labellum developed, about 0.1x as long as prementum.
Abdomen (Fig. 3a, d): Syntergite 1 + 2 with mid-dorsal longitudinal depression extending until ¼ to posterior margin.Syntergite 1 + 2 with at least 4 pairs of lateral marginal setae; tergite 3 with at least 4 pairs of lateral marginal setae and a pair of median marginal seta.

Diagnosis.
Eyes with only a few, scattered short setulae.Fronto-orbital plate dark silver pruinose.Postpedicel entirely dark brown.Facial ridge with setulae only at base.Prosternum bare.Thorax with silver pruinosity.Wing smoky; vein R 4+5 with setulae ending at the r-m.Costal spine very long, about 3 × the length of adjacent setae.Abdomen blackish, with silver pruinosity only visible on posterior view, occupying about anterior half of tergite 3 and 4. Male terminalia with surstylus setulose in frontal view.
Redescription of male.
Head (Fig. 4): Vertex about 0.13 × head width in dorsal view.Width of parafacial, measured at distance between inner margin of eye and antennal insertion, 2 × height of gena.
Abdomen (Fig. 4a, c): Syntergite 1 + 2 with mid-dorsal longitudinal depression extending until ½ to posterior margin.Syntergite 1 + 2 with at least 4 pairs of lateral marginal setae; tergite 3 with at least 4 pairs of lateral marginal setae and a pair of median marginal seta.
Terminalia (Fig. 5): Sternite 5 with slightly developed lobules, setulose, with basal plate long and slightly curved; sensilla "trichodea" present on distal portion.Epandrium broad in posterior view, setulose, and closed dorsally.Anterior epandrial process undeveloped.Cerci not fused, narrow, apically rounded and distally slightly tapered in posterior view.Surstylus somewhat narrow, not fused with epandrium, convex, with seven long setulae in frontal view; distally tapered in lateral view (Fig. 5A, C).Extension of dorsal sclerite of distiphallus ending in an expanded region.
Female.Following the description of Thompson (1963: 472), it differs from male by the following: head with vertex about 4x width of front.Ocellar setae weak, Remark.At the NHMUK collection the two male syntypes from the original description of Wulp were examined by D.M. Wood.One male presents a lectotype label and the other male a paralectotype label attached by Wood in 1989.However, the lectotype designation was not published.In the interests of nomenclatural stability and to restrict the name to a single specimen, the male syntype bearing Wood's lectotype label and the additional label "NHMUK 013933635" is hereby designated as lectotype of Comyops nigripennis Wulp 1891.poorly developed.Abdomen with silvery pruinosity on each tergite, occupying just anterior margin, about 1/5 of each segment.Male terminalia with surstylus presenting long setulae laterally on frontal view.
Redescription of lectotype male.
Head (Fig. 6a-c): Vertex about 0.1 × head width in dorsal view.Width of parafacial, measured at distance between inner margin of eye and antennal insertion, 2 × height of gena.Fronto-orbital plate with setulae throughout its length.Frontal vitta narrowed dorsally.Eye about 0.9 × the head height.Gena about 0.1 × eye height.Labellum developed, about 0.1x as long as prementum.
Abdomen (Fig. 6a, c): Syntergite 1 + 2 with mid-dorsal longitudinal depression extending until ½ to posterior margin.Syntergite 1 + 2 with at least 4 pairs of lateral marginal setae; tergite 3 with at least 4 pairs of lateral marginal setae and a pair of median marginal seta.
Terminalia (Fig. 7): Sternite 5 with slightly developed lobules, setulose, with basal plate long and slightly curved; sensilla "trichodea" present on distal portion.Epandrium broad in posterior view, setulose, and closed dorsally.Surstylus somewhat narrow, not fused with epandrium, convex, setulose in posterior view and with about 10 long setulae laterally on posterior view; distally tapered in lateral view (Fig. 7A, C).Extension of dorsal sclerite of distiphallus ending in a confluent region.
Female.Following the description of Thompson (1963: 472), it differs from male by the following: head with vertex about 4x width of front.Ocellar setae weak, proclinate-divergent.A pair of strong proclinate orbitals and between these but near the anterior orbital, a strong reclinate frontal seta.Abdominal tergite 1 + 2 with no marginal or discal setae, but a pair of strong lateral setae.
Head (Fig. 8a-c): Vertex about 0.11 × head width in dorsal view.Width of parafacial, measured at distance between inner margin of eye and antennal insertion, 2 × height of gena.Frontoorbital plate with setulae throughout its length.Frontal vitta narrowed dorsally.Eye about 0.76 × the head height.Gena about 0.13 × eye height.Prementum about 0.5 × head height.Labellum developed, about 0.1x as long as prementum.
Abdomen (Fig. 8a, c): Syntergite 1 + 2 with mid-dorsal longitudinal depression extending until ½ to posterior margin.Syntergite 1 + 2 with at least 4 pairs of lateral marginal setae; tergite 3 with at least 4 pairs of lateral marginal setae and a pair of median marginal seta.
Female.Unknown.Biology.Unknown.Ebenia spinosa (Bigot 1889)  Remarks.In the original description of Morinia trichopoda, Wulp 1891: 261) mentioned "Six male and two female specimens", however, at the NHMUK collection, only two males and one female could be found.These three syntypes were examined by D.M. Wood.One male presents a lectotype label and the other specimens a paralectotype label each attached by Wood in 1989.However, the lectotype designation was not published.In the interests of nomenclatural stability and to restrict the name to a single specimen, the male syntype that bears Wood's lectotype label and the additional label "NHMUK 013933635" is hereby designated as lectotype of Morinia trichopoda Wulp 1891.

Type material examined
Head (Fig. 9a-b, d): Vertex about 0.14 × head width in dorsal view.Width of parafacial, measured at distance between inner margin of eye and antennal insertion, 2 × height of gena.Fronto-orbital plate with setulae throughout its length.Frontal vitta narrowed dorsally.Eye about 0.8 × the head height.Gena about 0.16 × eye height.Labellum developed, about 0.1x as long as prementum.
Remarks.Jacques-Marie-Frangile Bigot (1818-1893) was a French dipterist who accumulated an exceptionally rich collection of material from the Neotropical region over the years.Mexico was frequently cited for type localities, enabling the description of numerous new species.However, there are two main problems with his species: (1) because of Bigot's brief and uninformative descriptions, "…without reference to the type specimens it is virtually impossible to recognize any of the genera and species which Bigot described…" (Crosskey 1971: 293) and (2) for his careless regard for nomenclature and orthography (see, e.g., Verrall 1889).The holotype of this species is a fine example of Bigot's procedure.One can read at the original label of the holotype male (Fig. 9D), by the handwriting of Bigot himself, "Homodexia id olim"; "id." meaning idem and "olim" for formerly, i.e., equal to the formerly genus.In addition, Bigot wrote "E.spinosula", and not Homodexia spinosa.Thus, Bigot, since the original description, probably had changed his mind and preferred to consider this species as belonging to Ebenia and not Homodexia, as Brauer (1898) noted.Additionally, Wulp 1891: 264) considered Homodexia spinosa with a close resemblance with Morinia (= Ebenia in part, sensu Wulp).On the other hand, Brauer (1898) considered that the characters of this species agree with the genus Thelairodes Wulp 1891.Probably following Brauer (1898), Guimarães (1971) placed this genus as belonging to Thelairodes, a placement followed by O'Hara et al. (2020).Herein, I could confirm Bigot's change of mind as seen in his label by showing that Homodexia spinosa is indeed a species pertaining to Ebenia as the diagnostic characters above shows.
Additional complexities for anyone studying Bigot's material are that his type-specimens are normally only known to the country and he never cites the names of the collectors.Most of the insects collected in Mexico, especially for the nineteenth century, were acquired in Europe through professional collectors, who explored Mexico for many years, visiting almost every state of the country.Thus, Papavero (1971) considered very likely that Bigot studied the collections gathered in Mexico by Louis Pilate (1816-1852), a French naturalist; by three naturalists that belonged to a Belgian commission charged by the government to undertake a scientific exploration that included Mexico: August Boniface Ghiesbreght (1810-1893), a Belgian zoologist; Jean Jules Linden (1817-1898), a Belgian botanist, and Nicholas Funck (1817-1896) a Luxembourgish, the artist of the expedition.Additionally, the naturalists, that are also known for sending part of their collections to Luigi Bellardi (1818-1889) in Italy, could also have been used by Bigot in his works: Auguste Sallé (1820-1896) a French traveler, Adrien Jean Louis François Sumichrast (1828-1882) a Swiss naturalist and professional collector, Henri Louis Frédéric de Saussure (1829Saussure ( -1905)), a Swiss mineralogist and entomologist, and Adolphe Boucard (1839-1905) a French ornithologist and collector.Thus, it is virtually impossible to state a precise locality for E. spinosa without at least the information of who, among those distinguished travelers and naturalists that visited different regions of Mexico, was the one that collected this specimen.