Thinophilus longicilia Evenhuis & Grootaert, 2002

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 : 432-437

Thinophilus longicilia Evenhuis & Grootaert, 2002

(Figs. 20, 21)

Thinophilus longicilia Evenhuis & Grootaert, 2002: 304 (Figs. 6–11). Type locality: Lim Chu Kang mangrove.

Type material. Holotype male and 1 male and 1 female paratypes from: SINGAPORE: Lim Chu Kang mangrove, beach at low tide, 13 October 2000 (leg. N. Evenhuis & P. Grootaert; holotype in ZRC). Other paratypes: SINGAPORE: 1 female, Mandai mangrove, 9 October 2000 (leg. P. Grootaert & N. Evenhuis); 1 male, Sungei Buloh mangrove, 6 October 2000, (leg. P. Grootaert & N. Evenhuis).

Additional material. SINGAPORE: 7 males, 13 females, Kranji Nature trail, mangrove, 28 March 2005, (reg. 25035, Si540, leg. PG) ; 1 female, Pasir Ris, mangrove, 4 December 2003, (reg. 23106, Si51, leg. PG) ; 1 male, 3 females, Sungei Buloh, mangrove, 9 December 2002, (reg. 22077, Si802, leg. PG) ; 20 males; 26 females, mangrove, 27 November 2003, (reg. 23090, Si184, leg. PG) ; 5 males, 13 females, mangrove, 28 March 2005, (reg. 25036, Si538, leg. PG) ; 1 female, mangrove, 22 June 2005, (reg. 25122, Si797, leg. PG) ; 3 males, mangrove, 6 July 2005, (reg. 25199, Si875, leg. PG) ; 2 males, 5 females, tree trunks in mangrove, 6 July 2005, (reg. 25201, Si884, leg. PG) ; 1 female, mangrove, 26 August 2005, (reg. 25321, Si1025, leg. PG) .

SMIP & MIP material: 1 female, Mandai , MM1 , mangrove, 19 May 2014 (reg. 30518, Si 2633, Mal.); 1 male, 2 females, Mandai , MM3 , mangrove, 26 May 2014 (reg. 30526, Si 2664, Mal.); 1 male, Pulau Ubin , PU2 , mangrove, 14 December 2013 (reg. 30317, Ma 6083, Mal. ); 1 female, Sungei Buloh, SB 2, mangrove, 11-Sep-2013 (reg. 30138, Ma 5934, Mal.) .

Fig. 20. Thinophilus longicilia Evenhuis & Grootaert, 2002 , male habitus.

Mip2016: 2 males, Sungei Buloh (SB5), 5 April 2016 (Ma 8854, leg. B. Lee) ; 1 female, Sungei Buloh (SB5), 4 May 2016 (Ma 8867, leg. B. Lee) ; 2 males, Sungei Buloh (SB5), 23 May 2016 (Ma 8879, leg. B. Lee) ; 1 male, Sungei Buloh (SB5), 30 May 2016 (Ma 8887, leg. B. Lee) ; 3 males, 10 females, Sungei Buloh (SB10), 28 March 2016 (Ma 8983, leg. B. Lee) ; 4 males, 3 females, Sungei Buloh (SB10), 5 April 2016 (Ma 8984, leg. B. Lee) ; 4 males, 6 females, Sungei Buloh (SB10), 11 April 2016 (Ma 8987, leg. B. Lee) ; 5 males, 1 female, Sungei Buloh (SB10), 18 April 2016 (Ma 8989, leg. B. Lee) ; 9 males, 8 females, Sungei Buloh (SB10), 4 May 2018 (Ma 8994, leg. B. Lee) ; 2 males, 4 females, Sungei Buloh (SB10), 16 May 2016 (Ma 8995, leg. B. lee) ; 1 male, 1 female, Sungei Buloh (SB10), 20 June 2016 (Ma 9000, leg. B. Lee) .

Diagnosis. Medium-sized species (4 mm) with black palpus, almost entirely dark antenna and all coxae black. Arista subapical. Legs black, except first tarsomere of all legs pale yellowish in male, pale brownish in female. Fore and mid legs with very long hairs on femora, tibiae and first tarsal segments. 5 subequal dc. Cerci black, medially fused.

Remarks. Thinophilus longicilia must be compared with T. comatus sp. nov. due to the presence of very long black bristles on the fore and mid leg. Thinophilus comatus sp. nov. has however no long ventral bristles at all on the mid tibia. These bristles are very long in T. longicilia .

Bionomics. Not enough data are available to define its microhabitat, though it seems mainly to occur in the back Etymology. This Thinophilus species is dedicated to Rudolf Meier (NUS), who is the driving force behind the barcoding and phylogeny studies of insects in Singapore.

Diagnosis. A large species (7.7 mm) with all coxae black. Apical ¾ of arista white. All legs adorned with long bristles and spines. Fore coxa set with short black hairs anteriorly. Propleural bristles white. Fore femur in apical half with 7 long anterior hair-like bristles; posteriorly in apical third with 3 strong spine-like bristles. Fore tibia with a very strong posterodorsal bristle on basal fifth. Hind femur dorsoventrally curved in middle, basal third strongly swollen, there with a row of strong bristles nearly as long as femur is wide; apical half of femur narrow, anteroventrally and posteroventrally set with a row of long fine bristles. Hind tibia ventrally with a double row of very long fine bristles, up to 5× as long as tibia is wide. Empodium on all legs well developed and much longer than pulvilli.

Fig. 21. Thinophilus longicilia Evenhuis & Grootaert, 2002 , male terminalia. A, Epandrium ventrally; B, Epandrium and cercus laterally; C, Cerci dorsally. Scale = 0.1 mm.

mangrove. Once, it was observed in large numbers on an area with black peat along a trail in Kranji Nature trail close to the waterfront.

Distribution. Singapore.

Thinophilus longicilia seems to be known only from the northern side of Singapore in the mangroves from Lim Chu Kang, Sungei Buloh, Mandai, Pasir Ris, and Pulau Ubin. It has not been reported from Semakau Island where its sister species T. comatus sp. nov. is very abundant. T. longicilia is not common overall, but is most abundant in Sungei Buloh.

Phenology. Thinophilus longicilia is present throughout the year but since there are not enough data from the long term study, no cyclic activity was observed.

Thinophilus meieri Grootaert & Evenhuis sp. nov. (Figs. 22–24)

Material examined. Holotype male, SINGAPORE: Sungei Buloh, SB 10, 16 May 2016 (reg. 4239, Ma 8997; leg. B. Lee, ZRC LKCNHM) . Paratypes: 1 male, Sungei Buloh, 19 August 2005, Mal 1 (reg. 25302; leg. P. Grootaert; body grinded for DNA sequencing ( Lim et al., 2010; hypopygium and legs conserved and figured: Fig. 23) ; 1 male, Sungei Buloh, SB10 (reg. 4101, Ma 8986; leg. B. Lee; ZRCBDP0085789 ), 5 April 2016 ; 1 male, 2 females, Sungei Buloh, SB 10, 18 April , 2016 (reg. 4147, Ma 8992; leg. B. Lee) ; 1 female, Pulau Ubin, PU1 , 9 November 2013 ( ZRCBDP0099551 ) .

Male. (Fig. 22) Body length: 7.7 mm; Wing length: 6.0 mm.

Head. Frons and face with dark metallic green ground colour, frons with blue reflections. Frons sunken between the eyes. Face wider than width of third antennal segment, clypeus bulging. Palpus yellow above, paler below, with short black bristly hairs. Rostrum large, dark brown with white hairs. 2 long diverging ocellars; 2 verticals nearly as long as ocellars, pointing forward; 2 postverticals longer than verticals. Postoculars black and uniseriate above, the favoris below composed of long white multiseriate hairs.

Antenna yellow. Scape brown at base, as long as postpedicel. Pedicel short, completely brownish, with short dorsal and ventral bristles only. Postpedical almost rounded, its tip a little produced, arista apico- dorsal. Arista about twice as long as all antennal segments together, base brown and apical 2/3 white.

Thorax and scutellum shining dark metallic green, seen from behind with blue reflections; no dull black spots. No acr; 6 strong dc almost equally long, prescutellar a little longer than preceding. Scutellum with 2 long marginals, with a lateral bristle at each side half as long as marginals. Propleural bristles white, 7 short upper and 7 much longer bristles below.

Legs yellow with black hairs and bristles. All coxae black, hind trochanter brown, all tarsomeres of fore and mid leg whitish, only apical tarsomere of fore and mid leg with apex darkened, apical two tarsomeres of hind completely brown.

Fore leg. (Fig. 23C). Coxa anteriorly densely set with short black bristles; apical bristles longer. Trochanter with short black hairs. Femur a little thickened in basal half; ventrally on basal quarter with a cluster of long hairs, as long as femur is wide, posteroventrally on basal half with a row of black bristles almost twice as long as femur is wide; in apical third with 3 strong, somewhat flattened black spine-like bristles, the preapical one with a curved tip. Anteroventrally in apical third with a row of long black bristles also much longer than femur Fig. 22. Thinophilus meieri Grootaert & Evenhuis sp. nov., male habitus.

is wide. Tibia shorter than femur, anteriorly near middle with strong bristles, middle one longer than tibia is wide; near base with a very strong black bristle pointing downward, the bristle at least 4× as long as tibia is wide (Fig. 23D). Anteriorly with a pair of closely set black bristles. Tarsomeres 1–4 with a pair of long fine apical bristles. LI: Length of femur, tibia and tarsomeres (in mm): 2.75: 2: 1: 0.37: 0.28: 0.18: 0.30.

Mid leg. Coxa with a long black exterior bristle. Trochanter with only some minute black hairs. Femur (Fig. 23E) strongly thickened in basal half, there with a cluster of ventral bristles half as long as femur is wide. Middle tibia shorter than femur. Anteriorly in apical half with 3 very strong bristles, apical most strongly curved. On basal third a strong posterior bristle. Preapical bristles very short. Tarsomere 1nearly as long as tibia and much longer than following tarsomeres together. All set with long fine apical bristles. LII: Length of femur, tibia and tarsomeres (in mm): 2.45: 2.12: 1.75: 0.38: 0.35: 0.35: 0.33.

Hind leg. (Fig. 22), Coxa with a long exterior bristle.Trochanters with only minute hairs. Femur dorsoventrally curved in middle, basal third strongly swollen, there with a row of strong bristles, about half as long as femur is wide. Apical half of femur narrow, anteroventrally and posteroventrally set with a row of long fine bristles. Hind tibia longer than femur (Fig. 23B), ventrally with a double row of very long fine bristles, up to 5× as long as tibia is wide. The tips of these bristles somewhat straggling. Crown of preapical bristles very long. The preapical bristles on tarsomeres 1–4 rather stronger than on the other legs. LIII: Length of femur, tibia and tarsomeres (in mm): 2.75: 2.88: 1: 0.80: 0.45: 0.30: 0.33.

Fig. 23. Thinophilus meieri Grootaert & Evenhuis sp. nov, male. A, Hind femur; B, Hind tibia and tarsomeres; C, Fore leg anteriorly; D, Detail of fore knee posteriorly; E, Mid femur; F, Hind tibia and tarsi.

Wing clear, without darker shades (Fig. 22). Veins black. Apical part of M 1+2 undulating near middle; Apical part of M 3+4 as long as tp. Anal vein indicated for basal half only. Haltere white, with a patch of small black hairs dorsally at base Squama white, with short white cilia.

Abdomen with a shining metallic green ground-colour. Tergites covered with short black bristles and somewhat longer marginal especially on Tergite 1. Sternites without bristles at most some minute white hairs. Male terminalia as in Fig. 24. Cerci about ¼ of the length of the venter, yellow and tip set with short white hairs. Cerci pointed, dorsally not fused. Surstyli with a dorsal and ventral arm (Fig. 24B).

Female. Favoris much shorter; colour pattern on legs identical to male, though the fore and middle tarsus are not so pale whitish. All femora equally thick, not swollen at all like in male. No adornments at all. All femora ventrally set with numerous short bristles. Hind legs not modified.

Etymology. The name refers to the small size of this species.

Diagnosis. Small species (2 mm) with yellow palpus and antenna. Fore coxa completely yellow but can be largely brown at base, posterior four coxae black; femora yellow, sometimes dorsally faintly brown, all tibiae and tarsi brownish, ventrally paler brownish. Fore tibia with a ventral row of long bristles on apical two thirds (twice as long as tibia is wide). All femora with some long ventral bristles. Fore femur without strong preapical posteroventral bristles, at most 1 stronger bristle. 4 dc, with a short bristle in front. No dark spots on mesonotum; wing uniformly brownish.

Male. (Fig. 25) Body length 2–2.29 mm; wing length 2–2.11 mm.

Head. Frons and face with shining dark metallic green ground colour. Face below middle, as wide as depth of third antennal segment. Epistoma a little concave on upper half, lower half flat, clypeus hardly protruding, about 1/3 length of epistoma, below broader than long. Palpus yellow with black bristly hairs.

Fig. 24. Thinophilus meieri Grootaert & Evenhuis sp. nov., male. A, Epandrium ventrally; B, Epandrium and cercus laterally; C, Cerci dorsally.

Remarks.The females are difficult to recognise and are easily confused with females of T. murphyi Evenhuis & Grootaert. In contrast to other species with hind femur and tibia bearing long soft hairs, Thinophilus nigrilineatus sp. nov. (Fig. 30) and the closely related to T. constrictus Parent, 1932 , T. meieri sp. nov. has the basal half of the hind femur swollen, whereas in the former two species the apical half is widened. In addition, fore and mid femora are yellow in T. meieri sp. nov. while black in T. nigrilineatus and T. constrictus .