Thinophilus singaporensis, Grootaert, 2018

Grootaert, Patrick, 2018, Revision of the genus Thinophilus Wahlberg (Diptera: Dolichopodidae) from Singapore and adjacent regions: A long term study with a prudent reconciliation of a genetic to a classic morphological approach, Raffles Bulletin of Zoology 66, pp. 413-473 : 459-460

Thinophilus singaporensis sp. nov.

(Figs. 48, 49)

Material examined. Holotype Male. SINGAPORE: Nee Soon (1°22′57.01″N 103°48′52.82″), marsh, 3 December 2003, (reg. 23101, Si271, leg. PG).

Paratypes: 1 male, same provenance as holotyp; 1 male, 2 females, Nee Soon, swamp forest, 3 December 2003, (reg. 23101, leg. PG) ; 1 male, Nee Soon, swamp forest, 9 March 2005, (reg. 25005, Si396, leg. PG) .

Etymology. The name refers to the type locality Singapore.

Diagnosis. Large species (5 mm). No ventral bristles on fore femur; a double row of long ventrals on mid femur.

Male. Head. Face not very wide, as wide as third antennal segment is wide. Clypeus protruding. A pair of long, strong ocellars, verticals shorter. A pair of postvertical about 1/3 length of ocellar. Postoculars uniseriate and black above, white below (favoris white, rather short).

Antenna (Fig. 48A) First antennal segment brown above, paler below; second segment completely black; third antennal segment brown in dorsal half, yellow below. Palpus yellow with short black bristles.

Thorax coppery green in ground-colour (probably no dull black spots on mesonotum). Hairs and bristles black. No acr. 5 dc, anterior 4 short, prescutellar long (nearly 3 times as long as the anterior dc). a pair of long marginal scutellars. A fine humeral, posthumeral longer but still finer, a strong notopleural.

Fig. 48. Thinophilus singaporensis sp. nov., male. A, Antenna; B, Mid femur.

Legs yellow, but posterior four coxae black, fore coxae yellow with brown base. Fore trochanter yellow with a brow dorsal patch. Mid and hind trochanters pale brown. Tip of fore tibia brown. Apical tarsomere of all legs completely brown.

Fore leg. Coxa anteriorly with a weak, black bristle and some minute pale hairs; a row of long black bristles at tip. Femur without ventral bristles, but a row of black pv, very short near base but growing longer toward tip of femur, longest as long as femur is wide. Tibia with 1 ad and 1 pd in basal quarter, 1 ad and 1 pd in apical third. Tarsomere 1 ventrally with a double row of spiny bristles.

Mid leg. Coxa with short anterior bristles and a weak exterior. Mid femur with a double row of ventral bristles; posterior row short in basal half (not as long as femur is wide), long in apical half (twice as long as femur is wide). Tibia with a short ad on basal fifth, a short pd slightly before basal fifth, a pd near basal third, a minute pv near basal quarter and a short one at apical quarter; a crown of strong preapical bristles.

Hind leg. Coxa with a weak external. Femur without ventrals, but with 2 anterior bristles near middle and an ad near tip. Tibia with 5 short dorsals, a strong pd at apical quarter and a crown of strong preapicals; a row of short ventral bristles in basal half, nearly as long as tibia is wide.

Wing brownish grey with black veins. Vein R 4+5 slightly converging to M 1+2, but ending parallel in costa. Apical part of M 3+4 almost 1.5 times longer than tp. Anal vein not reaching wing border. Haltere white. Squama white with long pale cilia.

Abdomen shining metallic green. Tergites covered with short black bristles. First tergite with long marginals, following tergites with short marginals. Sternites without hairs except for the apical border of sternite 4, there a row of short spinulose bristles.

Terminalia (Fig. 49). Cercus brown, with brown hairs. Surstylus black with a number of apical spinules.

Female. Similar to male but lacking the long ventral bristles on the mid femur.

Fig. 49. Thinophilus singaporensis sp. nov., male. A, Details of tip epandrium and epandrial lobe; B, Epandrium ventrally; C, Epandrium and cercus laterally.

Remarks. Thinophilus singaporensis sp. nov. should be compared with T. nitens Grootaert & Meuffels that has the fore femur with a row of ventral bristles in basal half, being nearly as long as femur is deep but shorter ventral bristles in mid femur. T. singaporensis sp. nov. has no ventral bristles on the fore femur but very long ventral bristles on the mid femur. In addition, T. singaporensis sp. nov. has the fore coxa anteriorly with a weak, black bristle and some minute pale hairs. In T. nitens the fore coxa bears long white hairs and a black bristle anteriorly.