Ropalomeridae

Ibáñez-Bernal, Sergio & Hernández-Ortiz, Vicente, 2012, The new genus Acrocephalomyia, and a new species of Ropalomera from Costa Rica, with additional records for other Mesoamerican species (Diptera: Ropalomeridae), Zootaxa 3478, pp. 553-569 : 567

Key to the genera of Ropalomeridae and their known species from Central America and Mexico

(modified from Ibañez-Bernal & Hernández-Ortiz, 2010)

1. Postpronotal bristles present............................................................................. 2

– Postpronotal bristles absent............................................................................. 10

2. Arista bare or microscopically setulose.................................................................... 3

– Arista with long rays or bipectinate....................................................................... 5

3. Face with median vertical carina; genal surface striated; scutellum bare on disc with only one marginal and one apical scutellar bristles; hind tibia weakly flattened. USA (Florida), Argentina.................................... Rhytidops Lindner

– Face with small median rounded tubercle; scutellum setulose on disc and with 2–5 scutellar bristles (including apicals); hind tibia strongly flattened.................................................................................. 4

4. Two postpronotal bristles; ocellar bristles well developed; posterior thoracic spiracle with more than 3 bristles; scutellum convex dorsally with 2–3 scutellar bristles....................................................... Kroeberia Lindner K. fuliginosa Lindner

– One postpronotal bristle; ocellar bristles absent; posterior thoracic spiracle with 1–3 bristles; scutellum weakly concave or grooved dorsally with 4–5 scutellar bristles................................................ Lenkokroeberia Prado L. chryserea Prado

5. Face with median vertical carina that ends as hump between antennal bases; posterior thoracic spiracle with 4–7 bristles; scutellum flattened on dorsal surface................................. Willistoniella Mik. ......................6

– Face with rounded protuberance distant from antennal bases; posterior thoracic spiracle with 1–3 bristles; dorsal surface of scutellum weakly concave....................................... Ropalomera Wiedemann. ...................8

6. Male with sternum 5 as long as 0.5 times width, with a long bristle on postero–lateral angle; surstylus long, so cercus not exceeding its basal half. Female tergum 7 with the posterior margin strongly concave and U-shaped; posterior sclerite of sternum 7 large, covering the anterior dorsal surface and reaching the level of posterior margin of tergum 7........................................................................................... W. ulyssesi Marques & Ale-Rocha

– Male with sternum 5 shorter than 0.4 times width, with 1–3 long bristles on postero-lateral angle; surstylus short, so cercus exceeding its basal half. Female tergum 7 with the posterior margin strongly concave and V-shaped; posterior sclerite of sternum 7 reduced leaving extensive membranous areas and at much reaching the level of lateral sclerotized projections of tergum 7................................................................................................... 7

7. Male with surstylus constricted at middle in posterior view, about 3 times its apical width, apex capitate. Female posterior sclerite of sternum 7 absent.................................................. W. spatulata Marques & Ale-Rocha

– Male with surstylus linear in posterior view, over 4 times its width, apex rounded. Female posterior sclerite of sternum 7 strongly reduced to two join lines............................................... W. pleuropunctata (Wiedemann)

8. Body coloration shining black, scutal and pleural vittae absent; abdomen and wings mostly black; scutellum bright brownish strongly projected dorsally and pointed apically in dorsal view................................... R. aterrima sp. nov.

– Body coloration dull dark, scutal and pleural vittae present, abdomen with pale pollinose patches and wings hyaline or partially fumose; scutellum dull, flat or slightly concave dorsally, apically blunt in dorsal view................................ 9

9. Two postpronotal bristles; scutellum slightly projected dorsally in lateral view, so an angle is formed to level of scutellar suture; lateral margins of scutellum constricted near the bases of marginal bristles in dorsal view................................................................................... R. latiforceps Ramírez-García & Hernández-Ortiz

– One postpronotal bristle; scutellum not projected dorsally in lateral view, so the scutal and scutellum surfaces do not form an angle; lateral margins of scutellum straight, not constricted near the bases of the marginal bristles in dorsal view.............................................................................................. R. femorata Fabricius

10. Arista furnished on all sides with flattened hairs; scutellum convex on dorsal surface with 2 scutellar bristles (including apicals); posterior thoracic spiracle with 5–6 bristles............................................... Mexicoa Steyskal Mexicoa mexicana Steyskal

– Arista bare, microscopically pubescent or bipectinate; scutellum variable dorsally with only one apical scutellar bristle; posterior thoracic spiracle with 1–4 bristles.................................................................... 11

11. Arista bare; face flat without tubercle, carina or cavities; inner vertical, ocellar and postocellar bristles absent............................................................................................ Acrocephalomyia gen. nov. Acrocephalomyia zumbadoi sp. nov.

– Arista micropubescent, bipectinate or long plumose; face with tubercle, carina or cavities; inner and outer verticals always present, ocellar and postocellar bristles variable............................................................. 12