Thinophilus lenachanae, 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 : 429-432

Thinophilus lenachanae sp. nov.

(Figs. 17–19)

Material examined. Holotype male, SINGAPORE: Sungei Buloh , 27 November 2003 (reg. 23090, leg. PG) . Paratypes: 1 male, 2 females, Sungei Buloh, mangrove, 28 March 2005, (reg. 25035, Si543, leg. PG) ; 1 female, Sungei Buloh, mangrove, 27 July 2005, (reg. 25272, Si1293, leg. PG) .

MIP2016 : 1 female, Sungei Buloh (SB4), 28 March 2016 (Ma 8819, leg. B. Lee) ; 1 male, Sungei Buloh (SB04), 5 April 2016 ; 3 females, Sungei Buloh (SB4), 11 April 2016 (Ma 8821, leg. B. Lee) ; 1 male, Sungei Buloh (SB6), 18 April 2016 (Ma 8899, leg. B. Lee) ; 1 male, Sungei Buloh (SB6), 30 May 2016 (Ma 8910, leg. B. Lee) ; 1 female, Sungei Buloh (SB04), 27 June 2016 ; 2 males, Sungei Buloh (SB04), 4 July 2016 ; 1 male, Sungei Buloh (SB06), 4 July 2016 ; 1 female, Sungei Buloh (SB04), 18 July 2016 ; 1 female, Sungei Buloh (SB04), 25 July 2016 ; 1 female, Sungei Buloh (SB04), 22 August 2016 ; 1 female, Sungei Buloh (SB04), 5 September 2016 .

Etymology. The species is dedicated to Lena Chan, Senior Director at the National Biodiversity Centre at NParks Singapore, who enthusiastically stimulated the long-term

Fig. 17. Thinophilus lenachanae sp. nov. male habitus.

RAFFLES BULLETIN OF ZOOLOGY 2018

research on Singapore mangroves. The present study would not have been possible without her continuous support.

Diagnosis. A medium-sized species with yellow palpus. Antenna dorsally brown, ventrally yellow. Arista not pubescent. Third antennal segment a little longer than high, with a rounded tip. All coxae black, hind trochanter brown; all femora black on basal two thirds with contrastingly yellow tips. Rest of legs yellow. Fore trochanter with at least four long bristles with a curved tip. Fore femur at base with a double row of long ventrals. Mid femur with two long ventrals near base and hind femur with a single row of long ventrals on basal two thirds. Hind tibia with a row of 3 to 4 long ventral bristles in apical half. 6 dc, almost equally long. Genital capsule pale brown, cerci yellowish with white hairs.

Male. (Fig. 17) Body length 4.0 mm; wing length 3.90 mm.

Head. Frons and face with shining dark metallic green ground colour. Face wide, narrowest just below antennae, wider than depth of third antennal segment. Clypeus protruding, about 1/3 length of epistoma. Palpus yellowish (appearing brown through dark rostrum below) with black bristly hairs. Rostrum large (a third of height of eye) dark brown with white hairs. Postcranium shining dark metallic green, concave. 2 long, diverging ocellars; 2 long (only slightly) shorter, converging verticals, pointing forward; no postocellars; 2 distinct postverticals, as longer as upper postoculars. Postoculars in upper third black and uniseriate; below white and longer; but near mouth a second row of long white bristle with a single bristle between the two rows. Antenna yellow on ventral half, dorsally as well as tip of third segment darkened. Second segment with lateral margin black; with long dorsal and ventral bristles. Third segment slightly longer than high; tip broadly rounded. Arista subapical, twice as long as antenna, black, not pubescent; basal aristal segment short.

Thorax and scutellum shining dark metallic green; no dull black spots. No acr; 6 long dc, almost equally long, anterior shortest, prescutellar longest. Scutellum with 2 marginals, Wing feebly brownish tinged. Veins black. Apical part of M 1+2 curved up near middle, from there on running parallel with R 4+5. Apical part of M 3+4 1.5 times as long as tp. Anal vein dark brown on basal half, further only indicated as a fold, not reaching wing margin. Haltere white. Squama white, with numerous white cilia.

Abdomen with a shining metallic green ground-colour. Tergites covered with short black bristles and somewhat longer marginals (those at side of first tergite longest). Sternites without bristles, only a minute white pubescence. Genital capsule and surstyli brownish, cerci pale yellowish with white hairs. Terminalia as in Fig. 19. Surstylus with a long thin ventral arm and a thick ventral arm (Fig. 19B). Cerci separated (Fig. 19C).

Female. In most respects identical to male, but without the long bristling on the legs.

Remarks. This species can be easily recognised in having all femora with basal two thirds black and apical third contrastingly yellow. The fore trochanter bears a row of about 6 long black bristles with somewhat curled tip.

Fig. 19. Thinophilus lenachanae sp. nov. male terminalia. A, Epandrium ventrally; B, Epandrium and cercus laterally; C, Cerci dorsally.

with a fine lateral hair at each side. 3 upper and 3 lower white propleural bristles.

Legs yellow with black hairs and bristles, but all coxae black with extreme tips paler brownish, posterior trochanter brown; all femora black with apical third yellow; apical tarsomere brown.

Fore leg. Coxa with long (longer than coxa is wide) black bristles (from middle downward), tip anteriorly with a row of long fine bristles with curled tip. Trochanter with at least 4 very long bristles with curled tip (Fig. 18D). Fore femur thickened in basal quarter (Fig. 18B); there bearing two rows of long ventral bristles with somewhat bent tip (bristles as long as femur is wide); a long, fine preapical pv. Tibia with 2 dorsals, 2 p and a crown of short apicals (Fig. 17). Tarsomeres with a pair of short apical bristles.

Mid leg. Coxa with a long black exterior, long black apicals. Trochanter with a long black ventral. Mid femur a little thickened in basal third, there with two very long fine, ventral bristles. A strong anterior on apical third (just on the transition of the black to yellow colour); a short preapical av and pv. Tibia with 3 ad 3 pd and a crown of long apicals.

Hind leg. Coxa with a long exterior. Femur swollen on basal two thirds, with a row of long ventrals extending on basal two thirds. Two strong anterodorsal bristles near apical third of femur. Tibia with a row of 2 long, fine ventral bristles near middle and 2 long posterodorsal bristle in apical quarter (their tip somewhat curled); 3 strong ad, 3 pd, and a crown of long apicals, dorsal bristle much longer than the others.

Distribution. Singapore, Thailand (Samoh & Grootaert, unpublished).