The genus Tachydromia Meigen (Diptera: Hybotidae) from the Afrotropics
Author
Shamshev, Igor
Author
Grootaert, Patrick
text
African Invertebrates
2010
2010-05-31
51
1
207
207
http://www.bioone.org/doi/abs/10.5733/afin.051.0106
journal article
10.5733/afin.051.0106
2305-2562
7913431
Tachydromia petrabilis
Smith, 1969
Fig. 12
Tachydromia petrabilis
:
Smith 1969: 73
, figs 82 (wing), 83 (right surstylus).
Type
locality:
South Africa
,
Drakensberg Mts, Royal Natal National Park.
Diagnosis: Recognised by a combination of the following characters: occiput almost entirely shining; prothoracic sclerites (including postpronotal lobe) with inconspicuous pruinosity; legs with all femora entirely brownish; wing with bands connected on cell r
1
; male mid femur with rows of unmodified anteroventral and posteroventral short setae.
Redescription:
Male
:
Length
: Body
1.5 mm
, wing
1.5 mm
.
Head: Eyes with posterior margin slightly produced beyond ocellar tubercle; vertex broader than frons in front of ocellar tubercle. Occiput, including vertex, entirely shining in
holotype
(very narrowly finely pollinose behind eyes in
paratype
female); 2 moderately long postvertical setae. Ocellar tubercle shining, ocellars minute. Frons shining, slightly widened toward ocellar tubercle. Antenna with postpedicel and stylus brownish, scape and pedicel somewhat paler. Postpedicel subglobular; stylus subapical, very long, nearly 3× as long as pedicel and postpedicel combined. Palpus unmodified, slender, shorter than proboscis, blackish; clothed in silvery setae, with rather short (slightly shorter than palpus) black subapical seta.
Thorax
: Black, almost entirely shining, prothoracic sclerites (including postpronotal lobe) with inconspicuous pruinosity, scutellum and mediotergite (= metanotum) densely tomentose. Postpronotal lobe large, elongate, lacking conspicuous setae. Mesonotum with 1 long notopleural, 1 similar postalar and 4 scutellars (lateral pair very short, apical pair somewhat longer than notopleural seta, subparallel); acrostichals lacking; dorsocentrals uniserial, mostly minute, in
holotype
prescutellar pair obscured by pin (in
paratype
prescutellars very short, nearly as long as lateral scutellars); mesosternum and metasternum bare between posterior four coxae.
Legs
: Fore and hind coxae yellow, mid coxa brownish basally; femora and tibiae brownish (the former paler on extreme base, rather yellowish on hind femur); tarsomeres 1 and 2 brownish apically, remaining tarsomeres entirely brownish. Coxae with yellowish unmodified setae. Fore femur thickened, pale pubescent ventrally, with yellowish anteroventral and posteroventral setulae becoming longer basally. Fore tibia slightly spindle-shaped. Mid femur slender, with rows of anteroventral and posteroventral spine-like setae (the latter darker and stronger). Mid tibia with short apical projection, bearing ventral spinule-like setulae. Hind leg unmodified, lacking prominent setae.
Wing
: Normally developed, rounded at apex, with unmodified venation; two broad brownish bands connected on cell r
1
. One short costal bristle present. Vein R
2+3
strongly arched about middle toward costa. Veins R
4+5
and M
1+2
parallel near wing apex. Vein CuM distinct throughout. Crossveins r–m and bm–cu broadly separated. Squama dusky yellow with concolorous fringe. Halter with pale knob and brownish yellow stem.
Abdomen
: Brownish, shining, covered with scattered black setae longer on pregenital segment; segments 1–7 unmodified. Terminalia small, rather elongate oval, blackish brown. We did not dissect the
holotype
male to examine the terminalia but
Smith (1969: 73)
indicates that they are very similar to
T. lilaniensis
. His fig. 82 is the right surstylus viewed from the inner side, which is subtriangular, with a deep notch on the lower (dorsal) margin, bearing several subapical spinules on inner side.
Female
.
As in male, but mid tibia with hardly prominent subapical projection, cercus brownish, long, slender, covered with minute setulae.
Holotype
(examined):
ơ
SOUTH AFRICA
:
KwaZulu-Natal
: on boulders / stream edge / 12.ix.63 /
1500 m
[hand-written]; Royal Natal National Park [
28°41.3'S
:
28°56.2'E
], Drakensberg Mts. / B. & P. Stuckenberg; running over lichenous boulders with the chalcid
Holceupelmus
[hand-written]; The chalcid was
Holceupelmus
sp.
[hand-written] R.D. Eady det. 1963;
HOLOTYPE
ơ
Tachydromia petrabilis
[species name hand-written] K.G.V. Smith (NMSA).
Note
: The
holotype
is in good condition.
Paratype
(examined):
^same
data as in
holotype
(
NMSA
)
.
Distribution:
South Africa
,
Lesotho
. This species may have a wide distribution because, according to labels (
Smith 1969
), it was collected over a long period including September, January and April. The flies were taken on boulders near a stream edge.
Remarks:
Smith (1969)
described this species after several specimens taken from three localities in the mountains of
South Africa
and
Lesotho
.