Chaetonerius ebejeri, Sepúlveda & De Carvalho, 2019

Sepúlveda, Tatiana A. & De Carvalho, Claudio J. B., 2019, Chaetonerius Hendel (Neriidae: Diptera) from the East African islands with description of four new species from Madagascar and the Comoros, Zootaxa 4567 (1), pp. 130-146 : 138-139

Chaetonerius ebejeri sp. n.

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Diagnosis. Presence of an underdeveloped antennal base ( Fig. 11 ). Several setulae between anterior margin of frons and anterior fronto-orbital seta. Middle fronto-orbital seta placed closer to anterior than posterior frontoorbital setae. Face dark yellow with brownish median sagittal stripe. Thorax with two narrow dorsocentral yellow stripes. Mid and hind coxae brown. Katepisternum with yellow spot posteriorly. Katatergite yellowish-brown. Abdomen brown without dorsal longitudinal yellow stripes on males and with one median longitudinal yellow stripe on females.

Male. Body length 6.5 mm; dark brown with small yellow region in head, thorax dorsal and pleuron ( Fig. 17 ).

Head. Anterior margin of frons slightly concave; fronto-orbital plate yellow and narrow; frontal vitta mostly black with median yellow stripe anteriorly, narrowing towards ocellar triangle; anterior fronto-orbital seta short, nearly half length of posterior fronto-orbital seta; vertex brown, bordered laterally by stripe of white pruinescence extending from fronto-orbital plate to occipital foramen, delineating the brown median occipital sclerite; vertex and median occipital sclerite not meeting at a right angle; area around insertion of outer vertical seta, inflated. Occiput brown with diffuse median yellowish-brown stripe; two long and two short postocular setae; four occipital setae. Lateral yellow postgenal setulae sparse. Frontogenal suture extends anteriorly beyond the parafacial, almost reaching the antennal socket ( Fig. 12 ). Palpus yellow. Antennae. Arista brown with base white, covered by short and sparse pubescence; arista inserted sub-apically; first flagellomere wide ovate with wide round apex; scape and pedicel short, together slightly less than length of first flagellomere.

Thorax. Dorsally with two narrow dorsocentral yellow stripes. Scutellum triangular, with curved margins; length of distal margin between scutellar apical setae, less than half the distance between prescutellar dorsocentral setae; median scutellar yellow stripe narrower than thoracic median brown stripe; discal scutellar seta half the length of anterior notopleural seta. Pleuron mostly brown with dorsal yellow stripe from dorsal half of proepisternal lobe to wing base and dorsal anepisternum. Proepisternum mostly yellow and setulose; with one ventral black seta same length as discal scutellar seta; proepisternal lobe with no protuberance. Anepisternum with yellow setulae posteriorly. Katepisternum with several yellow setulae posteriorly. Wings. Discretely infuscate around reaching point of veins R 2+3 and C and veins R 4+5; length 6.0 mm and width 1.7 mm. Legs. Fore coxa yellow with two anterolateral setae; mid and hind coxae brown. Femora brown with yellow ring on distal third; fore femora lost.

Abdomen. Sternite 6 brown and visor-shaped, expanded over a very small proximal region of epandrium ( Fig. 22 ). Distal margin of epandrium reaching anterior half of fourth abdominal segment ventrally; surstylus linear, measuring half the length of cercus; cercus wide linear, slightly tapering distally and as long as one third the length of epandrium; outer margin of phallapodeme presents a triangular sclerotization on distal third; pregonite linear; postgonite with rows of 2¯3 spines; distiphallus partially sclerotized and flattened, membranous medially, terminating in a lanceolate apex with two lateral sharp and partially sclerotized spikes.

Variation. Body length 5.7¯ 6.9 mm. Wing length 5.2¯ 6.3 mm and width 1.3¯ 1.8 mm. Apex of first flagellomere narrow. Fronto-orbital plate in one side with an additional seta near anterior margin. Occipital median yellow stripe paler and well-defined; two long and one short postocular setae. Posterior margin of scutellum slightly wider. Fore femur with anteroventral spine-like seta, interspersed between two short and one long inserted in a small tubercle; yellow ring on distal third diffuse.

Female. First flagellomere longer, with apex narrow. Fore coxa with one or none anterolateral setae. Femora brown; fore femur with one or two anteroventral setae no-spiny. Abdomen dorsally with one median yellow stripe. Oviscape shiny yellow to brownish-yellow with black apex.

Type Material (5 specimens), HOLOTYPE, Chaetonerius ebejeri ♂ Madagascar, Fianarantsoa Prov. Ranomafana National Park, Valbio Research Station , radio tower, S21°15'15", E47°25'18", 900m, (14-01) M. Hauser, S. D. Gaimari & R. Harin'Hala, 13–22.i.2014, ex. Malaise trap [ CSCA, 2248] . PARATYPES, 1♂ 1♀, same data as holotype [ CSCA, 2246 (dissected), 2247] ; 2♀, (1) Prov. Fianarantsoa, 7km W. Ranomafana, 1100m, 22–31 October 1988, W.E. Steiner (2) Malaise trap in small clearing, montane rain forest [ USNM, 514, 1583] .

Etymology. The new species Chaetonerius ebejeri is named after the entomologist Martin Ebejer for his contributions to the knowledge of the Afrotropical Diptera and valuable contribution to our research. The epithet is a noun in apposition.

Distribution. Madagascar (Vatovavy-Fitovinany Region).

Figures

FIGURES 11–15. Head lateral of the holotypes of the new species of Chaetonerius. 11. C. ebejeri, detailed area below the scape showing the underdeveloped antennal base pointed by the arrow; 12. C. ebejeri; 13. C. kotrbae; 14. C. kirkspriggsi; 15. C. madagasikara.

FIGURES 16–20. Male habitus of Chaetonerius of the East African islands. 16. C. kirkspriggsi (HT); 17. C. ebejeri (HT); 18. C. alluaudi [BMSA, 1858]; 19. C. madagasikara (HT); 20. C. kotrbae (HT). Abbreviation: HT, holotype.

FIGURES 21–25. Male genitalia of Chaetonerius of the East African islands, lateral and ventral views, square showing the zoomed apex of distiphallus (out of scale). 21. C. alluaudi [SANC, 1604]; 22. C. ebejeri [CSCA, 2246]; 23. C. kirkspriggsi [CSCA, 2241]; 24. C. kotrbae [USNM, 1633]; 25. C. madagasikara [USNM, 466].