Pontodromia pantai, Grootaert & Shamshev, 2012

Grootaert, Patrick & Shamshev, Igor V., 2012, The fast-running flies (Diptera, Hybotidae, Tachydromiinae) of Singapore and adjacent regions, European Journal of Taxonomy 5, pp. 1-162 : 44-47

Pontodromia pantai sp. nov.

Figs 73-78

Diagnosis

Fore tibia at middle with a anterodorsal bristle twice as long as tibia is wide. Left cercus bifurcate with right branch bearing five strong spines.

Description

Male LENGTH. Wing 1.6-1.7 mm.

HEAD. Black. Occiput subshining, finely pollinose. Two short vertical bristles present. Frons subshining, broadened towards ocellar tubercle. Anterior and posterior ocellars equally very long, black, former proclinate, latter lateroclinate. Antenna brown (postpedicel somewhat paler); pedicel with moderately long lower seta; postpedicel with lower margin somewhat convex, short, nearly 2.0 times longer than wide, with short dorsoapical extension; stylus nearly 4.0 times longer than postpedicel and about 2.0 times as long as scape, pedicel and postpedicel combined. Gena narrow. Palpus brownish yellow, small, rounded, with moderately long, fine seta. Proboscis brownish yellow.

THORAX. Brown, scutum somewhat paler on prescutellar depression. Prothoracic episterna lacking long seta just above fore coxa. Postpronotal bristle long, inclinate. Mesonotum with 1 long presutural supraalar, 2 notopleurals, 1 postsutural supra-alar, 1 postalar and 2 cruciate scutellars; acrostichals very short, arranged in 2 close rows; dorsocentrals short, uniserial, with 1 long median and 1 similar prescutellar pairs.

LEGS. With fore tarsus, mid and hind femora in apical part and mid and hind tibiae and tarsi brownish, otherwise brownish yellow to yellow. Fore coxa with strong bristle at base. Fore femur ( Fig. 73 ) swollen, thicker than mid femur, on apical half with long posteroventral bristles, ventrally at base with 3 strong, pale bristles. Fore tibia swollen, at middle with 1 anterodorsal bristle twice as long as width of tibia. Mid femur ventrally with minute bristles, except for pair of more prominent bristles at base. Mid tibia with anteroventral excavation on apical third ( Fig. 75 ). Tarsomere 1 somewhat flattened at base, further densely haired. Hind femur dorsally flattened from base to tip; at base rim of flattened area bears some distinctly erect bristles. Hind tarsomere 1 long and slender, nearly as long as following tarsomeres together.

WING. Normally developed, brownish infuscate, covered with uniform microtrichia. Costal vein with rather long setulae along anterior margin. Costal bristle long, brownish. Costal index: 33/19/36. Vein Rs originating far beyond middle of cell r 1, short, somewhat shorter than crossvein bm-cu. R 1 thickened. R 2+3 almost straight. R 4+5 and M 1+2 divergent on middle part of wing but parallel near wing margin. A 1 absent. Crossvein bm-cu strongly oblique. Crossvein r-m far beyond middle of cell bm. Halter brownish.

ABDOMEN. Tergites weakly sclerotised, unmodified; with inconspicuous unmodified setation. Sternites undivided, subrectangular, brownish. Gland-like structures absent.

TERMINALIA. ( Figs 76-78 ) Cerci separated, rather short; left cercus divided into 2 lobes, with left lobe digitiform, bearing 1 very long apical seta and 1 subapical seta, right lobe with five long spines. Epandrium completely divided. Left epandrial lamella fused to hypandrium, with 3 setulae in apical part. Left surstylus subrectangular, with several setae of different lengths ( Fig. 78 ). Right epandrial lamella subtriangular; with several unmodified setae of different lengths. Right surstylus very prominent, separated from epandrial lamella, small, as in Fig. 76 , with 3 long unmodified setae. Hypandrium with 1 very long seta apically. Phallus short. Two rod-shaped apodemes present.

Female

Legs unmodified. Abdominal segment 8 very narrow, elongate, with tergite and sternite separated; sternite 8 with apical part somewhat hinged. Cercus elongate oval, brownish. Otherwise as in male.

Material examined

Holotype ♂

SINGAPORE: Sungei Buloh, 28 March 2005, mangrove, sweeping (reg. 25037, leg. P.G.; in ZRC). Paratypes

SINGAPORE: 1 ♂, Sungei Buloh, 27 November 2003, mangrove, sweeping (reg. 23090, leg. P.G.); 7 ♂♂, 4 ♀♀, Sungei Buloh, 28 March 2005, mangrove, sweeping (reg. 25037, leg. P.G.).

MALAYSIA: 11 ♂♂, 19 ♀♀, Pulau Tioman, Monkey Bay, 14 July 2005, beach, sweeping (reg. 25216, leg. P.G.).

Etymology

The specific name 'pantai' means 'beach' or 'coast' in Malay.

Distribution

Malaysia (Johor), Singapore.

Habitat and seasonal occurrence

This species occurs on sandy beaches and in mangroves. Adults probably occur the entire year, but uncommon in disturbed habitats.

Remarks

Pontodromia pantai sp. nov. is very similar to the Papua New Guinean species P. nambis . A readily distinguishing character in P. pantai sp. nov. is the male fore tibia with a strong anterodorsal bristle twice as long as width of tibia. Such a bristle is absent in P. nambis . The left bifurcate cercus with right branch bearing five strong spines in P. pantai sp. nov., whereas the left branch in P. nambis bears only two spines. Additional undescribed species of Pontodromia are known from Thailand and Indonesia.

Figures

Figs 73-78. Pontodromia pantai sp. nov., ♂. 73. fore leg, anterior view. 74. mid tibia, anterior view. 75. mid leg, posterior view. 76. right surstylus, dorsal view. 77. epandrium and cerci, dorsal view. 78. left surstylus, lateral view.