Nepalomyia priapus, Grootaert, 2013

Grootaert, Patrick, 2013, New Nepalomyia Hollis (Diptera: Dolichopodidae) From Singapore And South Malaysia, Raffles Bulletin of Zoology 61 (1), pp. 103-116 : 107-109

Nepalomyia priapus , new species

( Figs. 9–11 )

Material examined. — Holotype male, SINGAPORE: Sime Forest , 3 Jun.2005, forest, Mal 1, (MS name: Si 681; reg. 25134, Si 905, coll. P. Grootaert).

Paratypes: 3 males, Sime Forest , 1 Apr.2005, forest, Mal 1, (reg. 25040, Si 618, coll. PG) ; 5 males, Sime Forest , 8 Apr.2005, forest, Mal 1, (reg. 25049, Si 681, coll. PG), DNA sequences in genbank ; 3 males, Sime Forest , 27 Apr.2005, forest, Mal 1, (reg. 25093, Si 790, coll. PG) ; 3 males, Sime Forest , 3 Jun.2005, forest, Mal 1, (reg. 25134, Si 905, coll. PG) ; 3 males, Sime Forest , 20 May 2005, forest, Mal 1, (reg. 25131, Si 909, coll. PG) ; 11 males, Sime Forest , 17 Jun.2005, forest, Mal 1, (reg. 25136, Si 913, coll. PG) ; 4 males, Sime Forest , 13 May 2005, forest, Mal 1, (reg. 25129, Si 938, coll. PG) ; 1 male, Sime Forest , 13 May 2005, forest, Mal 2, (reg. 25130, Si 940, coll. PG) ; 3 males, Sime Forest , 1 Jul.2005, forest, Mal 1, (reg. 25189, Si 1062, coll. PG) ; 2 males, Sime Forest , 3 Jun.2005, forest, Mal 2, (reg. 25135, Si 1074, coll. PG) ; 1 male, Sime Forest , 22 Jul.2005, forest, Mal 2, (reg. 25271, Si 1079, coll. PG) ; 7 males, Sime Forest , 3 Dec.2005, forest, Mal 1, (reg. 25434, Si 1318, coll. PG) ; 4 males, Sime Forest , 6 May 2005, forest, Mal 2, (reg. 25128, coll. PG) . 1 male, Nee Soon , 5 Apr.2005, swamp forest, Mal 2, (reg. 25047, Si 642, coll. PG) .

In genbank as Nepalomyia Si 681 ( Lim et al., 2009).

Etymology. — The species has a remarkable huge aedeagus and hence the name priapus (Latin) here used as noun, refers to the huge phallus of mythological Greek king Priapus.

Diagnosis. — A small species with triangular third antennal segment 1.6 times as long as wide. Tip of hypandrium, aedeagus and surstyli hidden in cavity of segments 4 and 5. Aedeagus much swollen, containing a black mass.

Male: Body length: 2.1–2.34 mm; wing length: 1.56–1.82 mm.

Head. Vertex brownish black, surpassing level of upper eye margin. Occiput concave. Face shining blue metallic, parallel-sided, as wide as the distance between the ocellar bristles; clypeus very feebly bulging out, grey dusted. Palpus dark brown, with a black apical bristle. Rostrum yellowish brown. Ocellar tubercle prominent. 2 strong black ocellars, 2 postverticals, nearly as long as the postocellars, but less strong; 2 tiny postocellars. Postocular bristles uniseriate, black. Antenna ( Fig. 9 ) brown: second segment with a circle of short marginal bristles and a long dorsal bristle. Third segment triangular, 1.6 times as long as wid. Arista 3.5 times as long as third segment: pubescence short in basal third, longer apically. Basal segment of arista swollen at apex.

Thorax brown, not shining, pleurae partly somewhat lighter coloured. A shallow prescutellar flattened area. Postscutellum with a median mound. Acr biseriate, half as long as dc. 5 dc (growing longer posteriad and ending in a long prescutellar). 1 long humeral and 1 shorter posthumeral, 1 short presutural, 2 short postsutural; 1 very long pre-alar; 1 very long post alar, 2 long notopleurals; scutellum with 2 strong marginals with a short hair at side. 1 long black propleural bristle, just above coxa.

Legs. Yellow with mid and hind coxae brown (mid coxa darkest). Bristles and hairs black. Fore coxa anteriorly with short black hairs ending in 4 long bristles near tip of coxa; near base a few minute erect hairs. Fore femur without bristles, bearing only 2 very short, hairlike preapical pv. Fore tibia without bristles. Mid coxa with numerous anterior bristles and 1 very long black bristle below middle. Mid femur with an anterior preapical, no posterior preapical. Mid tibia: 2 ad, 2 weaker pd; 3 bristles in apical crown. Hind coxa with a black exterior bristle, shorter than on mid coxa. Hind femur with an anterior preapical; no posterior preapical and no other bristles. Hind tibia with a thin and short, hairlike dorsal bristle near middle. A long dorsal preapical. No real apical crown of bristles, only a strong ventral. Posterodorsal comb short ( Fig. 10 ), with a denticle below. All tarsi slender and tapering toward tip. First segment of hind tarsus about half as long as second segment, a little thicker than following segment; with a brown basal “spur” pointing to tibia. Claws on all legs minute, symmetrical.

Wing faintly brownish tinged with brown veins. Basal joint of R 2+3 and R 4+5 swollen into a small node. Apical part of M 3+4 about 2.5 times as long as tp. Anal vein also brown, running parallel to posterior wing margin, but not reaching the margin. Squama with fan of long, black cilia. Halter with dark knob, but paler stalk.

Abdomen brown. Hairs and bristles on terga short, but all marginals very long. Sterna pale brownish and long marginals on sternites 3 and 4. Genital capsule ( Fig. 11 ) globular, dark brown. Cerci long, pale yellow, with a large yellowish leaflike bristle near middle; surstyli elongate, brown in contrast to paler cerci. Hypandrium pale, large and broad, symmetrical broadly furcate. Aedeagus much swollen in middle, its apex furcate, hidden inside fifth sternite, with a contrastingly black mass near middle, probably containing sperm. A long pale, epandrial bristle present, inserted on a short tubercle; with two very short bristles at base.

Female: Identical to male in most characters. No spur on hind metatarsus.

Remarks. — The huge aedeagus is unique in Nepalomyia . Remarkable is that it is filled in the middle with black rod-like structures that may be spermatozoids and thus this swelling represents a kind of spermatheca.

Figures

Figs. 9–11. Nepalomyia priapus, new species: 9, antenna; 10, hind basitarsus; 11, post abdomen.