The fast-running flies (Diptera, Hybotidae, Tachydromiinae) of Singapore and adjacent regions
Author
Grootaert, Patrick
Author
Shamshev, Igor V.
text
European Journal of Taxonomy
2012
2012-01-06
5
1
162
journal article
10.5852/ejt.2012.5
e809cd3a-36bb-413d-9f19-70837d7db34b
3715167
B69F002A-C1A0-439D-9477-62BFA87DEAD7
Drapetis pantai
sp. nov.
Figs 92
,
105-107
Diagnosis
Rather small species; antenna brownish yellow; palpus brownish; legs brownish yellow, hind tarsomere 1 with some longer ventral spinules near base; halter pale.
Description
Male
LENGTH. Wing
1.5-1.6 mm
.
HEAD. Black. Occiput subshining, finely pollinose. Two long vertical bristles present. Frons subshining, broadened towards ocellar tubercle. Anterior ocellars long, yellow; posterior ocellars minute. Antenna brownish yellow, postpedicel somewhat darker; pedicel with moderately long lower seta; postpedicel with lower margin somewhat convex, rather long, 2.5-2.8 times longer than wide; stylus nearly 3.0 longer than postpedicel and about 1.5 times longer than scape, pedicel and postpedicel combined. Palpus brownish, with moderately long subapical seta.
THORAX. Black. Anepisternum pubescent. Prothoracic episternum with 1 long upturned bristle just above fore coxa and some setulae on upper part. Postpronotal bristle not prominent. Mesonotum with 2 notopleurals, 1 postsutural supra-alar, 1 postalar and 4 scutellars (inner pair very long, cruciate; outer pair very short); scutum entirely covered with short, pale uniform (except for 1 pair of long prescutellars) setulae.
LEGS. Brownish yellow with hind femur, all tibiae and tarsi darker in different extent (in darker specimens hind femur and all tibiae brownish). Coxae and trochanters with unmodified setation. Fore femur somewhat thickened. Femora and tibiae mostly with inconspicuous setation. Mid femur with 1 anterior subapical bristle. Hind femur slender, with 3-4 longer anteroventral subapical setae (
Fig. 92
). Hind tibia with slightly prominent apical projection. Hind tarsomere 1 with some longer ventral spinules near base.
WING. Normally developed, hyaline, covered with uniform microtrichia; veins yellowish to brownish yellow. Costal vein with short setulae along anterior margin. Costal bristle short, brownish. Costal index: 50/16/47. Vein Rs originating before middle of cell r
1
(closer to humeral crossvein), nearly as long as crossvein bm-cu. R
1
thickened, meeting costa about middle of wing. R
2+3
evenly bowed toward costa, meeting costa beyond middle of wing. R
4+5
and M
1+2
convergent in apical part. R
4+5
slightly sinuate. A
1
absent. Crossvein bm-cu somewhat oblique. Crossvein r-m near middle of cell bm. Halter pale.
Figs 105-107.
Drapetis pantai
sp. nov.
, ♂ terminalia.
105
. right surstylus, dorsal view.
106
. epandrium and cerci, dorsal view.
107
. left surstylus, lateral view.
ABDOMEN. With tergite 1 pale yellow, tergites 2-7 brownish, rectangular, of subequal width, with scattered setulae, tergites 3 and 4 with squamiform setae laterally; segment 8 brown. Sternite 2 divided, sternites 3 and 4 with excision posteriorly. Gland-like structures present between tergites 3-4 and 4-5.
TERMINALIA. Small, black (
Figs 105-107
). Cerci separated; left cercus broad (
Fig. 106
), subrectangular, with numerous unmodified setae of different lengths; right cercus greatly reduced, represented as narrow, bacilliform sclerite bearing several short setulae. Epandrium completely divided. Left epandrial lamella fused to hypandrium, lacking setae in apical part. Left surstylus (
Fig. 107
) bilobed; upper lobe rather digitiform, with numerous unmodified setae; lower lobe somewhat shorter and broader, truncate, with several unmodified setae. Right epandrial lamella (
Fig. 106
) subtriangular, covered with numerous unmodified setae of different lengths. Right surstylus bilobed (
Fig. 105
); upper lobe broad, with several long unmodified setae; lower lobe somewhat narrower and longer, with unmodified setae. Hypandrium reduced, lacking setation. Phallus short. Two rod-shaped apodemes present.
Female
Unknown.
Material examined
Holotype
♂
SINGAPORE
: Chek Jawa,
15 December 2005
, mangrove, sweeping (reg. 25452, leg. P.G.; in ZRC).
Paratypes
SINGAPORE
:
1 ♂
, Chek Jawa,
15 December 2005
, mangrove, sweeping (reg. 25452, leg. P.G.).
MALAYSIA
:
3 ♂♂
, Pulau Tioman, Juara,
20 July 2005
, river, sweeping (reg. 25244, leg. P.G.).
Etymology
The specific name 'pantai' means beach or coast in Malay.
Distribution
Malaysia
,
Singapore
.
Habitat and seasonal occurrence
This species is found in mangroves, recorded in July and December.
Remarks
This species resembles representatives of the
D. assimilis
and
D. convergens
groups (
sensu
Kovalev 1972
). However, the new species is likely a member of a hitherto unrecognised group within
Drapetis
, defined on the basis of the following features: prothoracic episternum with 1 long upturned bristle just above fore coxa, tergites 3 and 4 with squamiform setae.