Stilpon laawae Shamshev & Grootaert, 2004

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 : 130-132

Stilpon laawae Shamshev & Grootaert, 2004

Figs 210-213

Stilpon laawae Shamshev & Grootaert, 2004b: 323 .

Diagnosis

Body length about 1.5 mm, wing length 0.9-1.2 mm. Thorax almost wholly yellow, scutum with small brownish patch above wing base. Postpronotal bristle slightly prominent. Acrostichal and dorsocentral bristles extending to base of scutellum. Legs largely yellow, fore tibia (except base) and fore tarsomere 1 brown. Hind trochanter lacking spinules. Mid femur slender, with 4 long yellowish bristles in basal part. Mid tibia lacking prominent ventral spinules. Wing normally developed, finely infuscate. R 2+3 present, nearly 2.0 times longer than Rs. Distance between apices of R 2+3 and R 4+5 about 2.0 times longer

130

than distance between apices of R 1 and R 2+3. R 4+5 and M slightly divergent and evenly arcuate in apical part. Halter with black, elongate knob, contrasting with pale yellow stem. Abdomen lacking gland-like structures. Male terminalia lacking spines; left surstylus without surstylar comb.

Material examined

SINGAPORE: 1 ♂, Chek Jawa, 2 December 2003, mangrove, Mal 1 (reg. 23097, leg. P.G.); 1 ♂, Chek Jawa, 11 December 2003, mangrove, Mal 1 (reg. 23119, leg. P.G.); 1 ♂, Chek Jawa, 22 December 2005, mangrove, Mal 1 (reg. 25455, leg. P.G.).

MALAYSIA: 1 ♂, 2 ♀♀, Pulau Tioman, Paya, 19 July 2005, secondary forest, sweeping (reg. 25238, leg. P.G.); 1 ♂, 4 ♀♀, Pulau Tioman, Paya, 19 July 2005, secondary forest, sweeping (reg. 25239, leg. P.G.).

Distribution

Malaysia, Singapore, Thailand.

Habitat and seasonal occurrence

In Thailand this species is known from two localities, respectively in central and northeastern Thailand, with records from the beginning of September to the beginning of October. In Singapore this species was taken from secondary forests and mangroves, with all records from only December, whereas in Malaysia this species was taken in July.

Remarks

The species was only known previously from Thailand and is recorded here for the first time from Singapore and Malaysia. Stilpon laawae belongs to the S. seeluang species group and, currently it is the only member of this unit found in Singapore. Note that there are small differences in the structure of the male genitalia between the Singapore and Thailand populations, but we do not think it would be them as different species.

Figures

Figs 210-213. Stilpon laawae, Shamshev & Grootaert, 2004, ♂ terminalia (Material Singapore). 210. right surstylus, dorsal view. 211. epandrium with cerci, dorsal view. 212. left surstylus, lateral view. 213. cerci, right lateral view. Scale bar= 0.1 mm.