Brachygasterina stuebeli ( Röder, 1886 ), Roder, 1886

De Carvalho, C. J. B. & Pont, A. C., 2006, Taxonomy, cladistics and biogeography of the South American genus Brachygasterina Macquart (Diptera: Muscidae), Zootaxa 1151, pp. 1-26 : 11-13

Brachygasterina stuebeli ( Röder, 1886) ( Figs 3 , 8 , 16 )

Hydrotaea stuebeli Röder, 1886: 269 .

Redescription

Female. Head: frons broad, at narrowest point 0.34–0.36 of head width ( Fig. 3 ). Eye with long and dense hairs ( Fig. 8 ); when the head is viewed from the front, the hairs are about as long as width of fronto­orbital plate ( Fig. 3 ). Fronto­orbital plate matt, blackish; parafacial, face and gena brownish­grey pruinose; occiput metallic blue to violet. 7–8 pairs of frontal setae; 1 strong and 1–2 weak reclinate orbital setae. Facial ridge with setulae reaching almost to level of aristal insertion. Parafacial and gena broad, in lateral view the former at least 0.5 of first flagellomere width ( Fig. 8 ). Proboscis mainly shining, dusted behind. Palpus black.

Thorax. Ground­colour subshining dark metallic violet­blue, dulled by pruinescence in posterior view. Mesonotum with 2 stripes (very indistinct in lectotype). 2+3 developed acrostichals (3+ 3 in lectotype); 2 strong posterior intra­alar, first weaker; prealar strong, subequal to anterior notopleural seta; notopleuron with dense setulae, mostly around second notopleural seta. Scutellum laterally setulose; with strong apical, basal and lateral setae, and corresponding setae on disc. One strong proepisternal seta and 3–4 hairs; 2 strong proepimeral setae and many long hairs. Katepisternals 2+3. Meron bare. Katatergite distinctly setulose.

Legs. Dark brown. Fore tibia without posterior seta. Mid femur with 2 short anterior and 4 posterior preapical setae. Mid tibia with 3 posterior setae, without anterodorsal or ventrals. Hind femur with a row of strong anteroventral setae, and with strong posteroventrals in basal half; 2–3 anterodorsal and 3 anteroventral setae; dorsal preapical strong, anterodorsal preapical weak, without posteroventral apical.

Wing. Smoky, veins dark brown. Veins bare, except costa. Crossvein dm­cu very sinuous. Vein M slightly upcurved towards R4+5. Calypters dark brown, lower one slightly longer than upper one. Knob of haltere dark brown.

Abdomen. Subshining metallic blue­violet, matt in posterior view. Sternite 1 bare.

Ovipositor: see Fig. 16 .

Measurements (n=2): Body length, 8.0– 8.7 mm. Wing length, 7.8–8.3 mm. Lectotype: body 10 mm, wing 9 mm.

Type material examined

Lectotype, female (see notes on type locality below), in MLUH, by present designation and labelled accordingly; it is the only surviving syntype. Old white handwritten label: “Paramo / 3600 Met. / Columbia ” [the “ Columbia ” in a different hand from the rest, and neither in Von Röder’s handwriting]; Von Röder’s handwritten white label: “Hydrotae­ / a / Stübeli / n. sp.”. Labelled (printed) by ACP: “ LECTOTYPE female / Hydrotaea / stuebeli / Von Röder, 1886 / des. A. C. Pont 2004 ” (see also Pont 2004).

Other material examined. ECUADOR. Pichincha, 35 km Tandopi, 24–29.vi.1975 (S. Peck), 1 female ( FMNH); Napo, 42 km NW Baeza, 3300’ [feet], 2–6.iii.1976 (S. Peck), 1 female ( DZUP).

Remarks

The body of the lectotype is rather dirty and right fore leg is missing, otherwise it is well preserved. According to the labels, the other specimens were collected in carrion traps and on bamboo shrubs between 1100 and 3600 metres, the latter on páramo.

Notes on the type­locality: The Diptera collected by Alphons Stübel, one of greatest of the early collectors in South America, were identified and published by Röder (1886). Stübel spent nine years in this region after arriving in Santa Marta, Colombia, in 1868. He subsequently visited several other countries, mainly studying geology and especially vulcanology but also collecting flies (see Papavero 1973). Compared with the present time, Colombia was a very different country when Stübel collected the female of B. stuebeli at an altitude of 3600 metres, embracing the whole north­west part of the South American continent. The lectotype label mentions Páramo in Colombia as the typelocality. However, “Páramo” is a type of vegetation, subdivided into subpáramo, páramo and super páramo ( Hammer 1974), and is characteristic of the South American tropical highlands, being found above 3000 metres in northern Peru, Ecuador, Colombia and Venezuela. It seems probable that the “Páramo” of the lectotype label refers to the vegetation type and is not the name of town or city in Colombia.

According to Papavero (1973: 310), Stübel made an excursion to Quito ( Ecuador) and its neighbourhood from April to June 1871, and in May, June, October to December 1873 to several localities in Ecuador, including Páramo de Calacali at 3600 metres. This is the only locality where “Páramo at 3600 metres” is clearly stated (see Papavero 1973), although there were other localities at or above 3600 metres during this entire journey. It is difficult, if not impossible, to establish the type­locality of B. stuebeli with certainty, but on the basis of Stübel’s 1873 itinerary we propose to fix Páramo de Calacali in Ecuador as the type­locality of B. stuebeli (map, Fig. 19 ). Other localities in Ecuador for B. stuebeli are known to us (see the material listed above).

Geographic distribution

Ecuador.

Figures

FIGURE 19. Geographic distribution of the sister groups Brachygasterina and Palpibracus, with selected cladogram superimposed. Symbols: () B. andina, () B. major Malloch, (Π) B. stuebeli (Röder), () B. valdiviensis (Pamplona & Couri), (o) B. violaceiventris Macquart. Only species of Brachygasterina are shown. Brachygasterina fulvohumeralis was not included on the map. The stippled area shows the range of species of Brachygasterina and Palpibracus in Chile and Argentina. See text for explanation.

FIGURES 1 – 5. Female head, frontal view. 1. Brachygasterina andina. 2. B. major. 3. B. stuebeli. 4. B. valdiviensis. 5. B. violaceiventris. Scale bar: 1 mm.

FIGURES 6 – 12. Head, lateral view. 6. Female, Brachygasterina andina. 7. Female, B. major. 8. Female, B. stuebeli. 9. Female, B. valdiviensis. 10. Female, B. violaceiventris. 11. Male, B. major. 12. Male, B. violaceiventris. Scale bar: 1 mm.

FIGURES 15 – 16. Female terminalia, ventral view. 15. Brachygasterina andina. 16. B. stuebeli. Abbreviation: spmt, spermathecae. Scale bar: 1 mm.