Notes on the Phycini of southern Africa with the description of a new genus and two new species (Diptera: Therevidae: Phycinae)
Author
Lyneborg, Leif
Zoological Museum, Copenhagen, Denmark
text
ANNALS OF THE NATAL MUSEUM
1987
1987-12-31
28
2
467
474
journal article
269420
http://doi.org/10.5281/zenodo.8380588
2c36411f-dde7-4a7e-97a1-206ae5f62c39
https://hdl.handle.net/10520/AJA03040798_396
8380588
Genus
Stenogephyra
gen. n.
Etymology:
stenos
= narrow;
gephyra
= bridge.
Gender: feminine.
Type
species:
Stenogephyra torrida
sp. n.
, present designation. Diagnosis
Small, blackish, slender-bodied species. Eyes widely separated in both sexes, frons about 3 times as wide as ocellar tubercle and polished black (
Fig. 7
). Face strongly protruding, forming a polished black convex callus below antennae. Gena wide. Scape very short; first flagellomere 4-5 times as long as scape, longest in O. Flagellar style very minute, obviously one-segmented, the usual apical spine (cf.
Figs 8-9
) not discernible. Palpus two-segmented, apical segment longer than basal segment. Proboscis short.
Thoracic chaetation: 2-3 np, 1 sa, 1 pa, 0-1 dc, 1 sc. Mesonotal pile black and uniform. Prosternum bare. Pleura practically without any pile. Ambient vein terminating at vein MI' Vein M2 usually abbreviated and not reaching wing-margin. Cell m3 petiolate. Cell r4 very slender, 4-6 times as long as wide at apex, veins R4 and Rs being nearly straight. Proximal end of discal cell pointed or closed by a very short, transverse cross-vein. Wings unpatterned. Mid coxa without pile on posterior surface. All femora without setae. Tibiae short, with few and short setae. Setae of mid and hind tarsi very short.
Abdomen short and wide, nearly cylindrical, in 0 suddenly tapering from segment 5 onwards, in <i' more gradually tapering. Dorsum shiny black with a short pile.
♂
terminalia (
Figs 10-18
). T8 (
Fig. 18
) and S8 (
Fig. 17
) of a simple rectangular shape. Also epandrium (
Fig. 11
) simple, without lateral projections. Ventral epandrial sclerite (
Fig. 12
) as in
Phycus
,
large, free, nearly as long as epandrium; not attached to aedeagus. Cerci wedge-shaped, short. Gonocoxites (
Fig. 13
) separated ventrally; no remnant of a hypandrium. Each gonocoxite with a narrow sclerotised bridge on inside (as in some Xestomyzini, see Lyneborg 1972), proximally to the insertion of the gonostylus. Dorsal apodeme of aedeagus connected to dorsal edge of gonocoxites via a sclerotised bridge. Distiphallus a short, rather wide, apically sharply pointed, tube (
Fig. 16
). Ventral apodeme very short and spoon-shaped. Ejaculatory apodeme with enlarged distal portion.
Figs 6-22.
Stenogephyra
gen. n.
6-21.
S. torrida
sp. n.
6. 7. Male head in frontal view. B. Male antenna. 9. Female antenna. 1O-1B. Male terminaha. 10. Male genitalia in lateral view. 11. Epandrium and cerci in dorsal view. 12. Epandrium, cerci and ventral epandrial sclerite in ventral view. 13. Gonocoxites with gonostyli in ventral view. 14. Left gonocoxite with ~onostylus and aedeagal complex in dorsal view. 15. Right gonocoxite with gonostylus in mterior view. 16. Aedeagus in lateral view. 17. Sternite B. lB. Tergite B. 19-21. Female terminalia. 19. Sternite B. 20. Subgenital plate and vaginal apodeme. 21. Tergite B, tergite 10 and cerci in dorsal view. 22.
S. minuta
sp. n.
, male antenna. Scale: 1 mm for 6 and 7,0,5 mm for the rest.
♀
terminalia (
Figs 19-21
). T8 (
Fig. 21
) large and squarish, its posterior margin not distinctly demarcated. T9 absent. TIO strongly constricted in mid-line, with 8-9 setae on each side. Cerci wedge-shaped as in 0'. S8 (
Fig. 19
) broadly spindleshaped and uniformly pilose, posteriorly with a deep slit which continues into an infolded penial guide. Vaginal apodeme (
Fig. 20
) broadly ring-shaped anteriorly, while posterior portion is open and horseshoe-shaped. S9 absent. Subgenital plate squarish with a low incision into posterior margin.
Distribution
The genus will probably prove to be restricted in distribution to the western Cape Province and Namibia.
Relationship
Phycus
and
Stenogephyra
form a monophyletic group. They share the following synapomorphic characters: (a) first flagellomere elongate; (b) femora without setae; (c) hypandrium vestigial or absent.
A
number of symplesiomorphic character states should also be mentioned. These are: (a) male eyes broadly separated; (b) palpus two-segmented; (c) prosternum bare; (d) ventral epandrial sclerite large. Autapomorphic characters for
Stenogephyra
are as follows: (a) face protruding; (b) flagellar style one-segmented and obviously without apical spine; (c) ambient vein terminating at M1.
Key to species of
Stenogephyra
1. Vein M2 usually abbreviated; its apex separated from wing-margin by a distance equal to width of discal cell (
Fig. 6
). Three pairs of notopleural setae. One pair of dorsocentral setae....................... ... ...
torrida
sp. n.
Vein M2 usually complete to wing-margin. Two pairs of notopleural setae. Dorsocentral setae not distinct from the usual mesonotal pile ..
minuta
sp. n.