Chaetonerius Hendel, 1903

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 : 134-135

Key for the identification of Chaetonerius Hendel from the East African islands

1 Occiput lateral and postgena in a right angle on meeting point with occiput posterior ( Fig. 14 ). Face blackish-brown. Proepis- ternum inflated. Fore coxa mostly brown. Palpus brown............................... C. kirkspriggsi sp. n. ( Fig. 16 ). - Occiput lateral and postgena curved on meeting point with occiput posterior. Face mostly to completely yellow. Proepisternum flattened. Fore coxa yellow. Palpus yellow.................................................................. 2

2. Underdeveloped antennal base present ( Figs 11, 12 , indicated by an arrow). Abdomen brown on males and brown with one median longitudinal yellow stripe on females............................................ C. ebejeri sp. n. ( Fig. 17 ).

- Antennal base completely absent. Abdomen brown with two median longitudinal yellow stripes....................... 3

3. Mid and hind coxae yellow. Face dark yellow with median sagittal brownish-yellow to blackish-brown stripe ( Fig. 3 ). Katepisternum brown ventrally with dorsal half paler to completely yellow................... C. alluaudi (Giglio-Tos) ( Fig. 18 ).

- Mid and/or hind coxae brown. Face dark yellow with no sagittal blackish-brown stripe, at most with a median darkening, not contrasting. Katepisternum completely brown............................................................... 4

4 Thorax dorsally with one median brown V-shaped stripe. Mid and hind coxae brown. Cercus parallel sided with rounded apex, which has very long and thick setae resembling claws ( Fig. 25 )....................... C. madagasikara sp. n. ( Fig. 19 ).

- Thorax dorsally with V-shaped brown stripe partially divided medially by one gray pruinose narrow stripe; in some cases, the brown stripe fades posteriorly. Mid coxa partially to completely brown and hind coxa yellow. Cercus narrowing distally with slightly pointed apex and sparse, thin and short setae ( Fig. 24 )............................. C. kotrbae sp. n. ( Fig. 20 ).

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 1–6. Chaetonerius alluaudi. 1. Head laterodorsal; 2. Head lateral; 3. Head lateroventral; 4. Head dorsal; 5. Thorax lateral; 6. Thorax dorsal.

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].