Platypalpus seedam, Grootaert & Shamshev, 2006

Grootaert, Patrick & Shamshev, Igor, 2006, The genus Platypalpus Macquart (Diptera: Hybotidae) from Northeast Thailand with comments on the species groups in the Oriental region, Journal of Natural History 39 (47), pp. 4031-4065 : 4051-4053

Platypalpus seedam sp. nov. (female)

Etymology

The name ‘‘seedam’’ refers to the black thorax (‘‘see dam’’ means ‘‘black colour’’ in Thai).

Diagnosis

A black species with one pair of verticals; antenna brownish, arista white, postpedicel 5.0 times longer than wide, arista nearly 2.5 times longer than postpedicel; mesopleuron largely subshining, sternopleuron shining; legs with yellow femora and brownish tibiae and tarsi.

Material examined

Holotype: female, Thailand, Loei province, Na Haeo , 15–22 August 2003, Malaise trap (2) (leg. P. Grootaert and Siriluck Intarasri).

Male

Unknown.

Female

Body length 2.9 mm; wing length 2.3 mm.

Head. Black in ground-colour, with occiput, ocellar tubercle and frons subshining, face shining. Occiput clothed with dark (mostly in upper part) and pale bristly hairs, bearing two dark moderately long, inclinate verticals. Ocellar tubercle with two moderately long, dark bristles and two minute setulae. Antenna brownish, arista white, thick pubescent. Postpedicel 5.0 times longer than wide. Arista 2.4 times longer than postpedicel and 1.5 times longer than scape, pedicel and postpedicel combined. Palpus wholly yellow, small.

Thorax. Wholly black; humerus, mesonotum and sternopleuron shining, otherwise thorax finely pollinose, subshining. Humerus with one very short bristle and few setulae. Mesonotum with one very short presutural supra-alar, two dark notopleurals (anterior one shorter and thinner), one postalar (similar to posterior notopleural) and four scutellars (outer ones very short, thin; inner ones long, cruciate); some scattered setulae present behind humerus, on notopleural depression, supra-alar space and postalar callus. Acrostichals very short, prominent in anterior part of mesonotum, arranged in two rows, wide apart, few in number. Dorsocentrals arranged in one regular row, divergent in anterior part of mesonotum, mostly very short (two pairs of prescutellars longer).

Legs. Hind coxa brownish basally, femora almost wholly yellow (with brownish tinge dorsally), tibiae brownish (especially fore tibia), tarsi brownish yellow. Fore femur somewhat thickened in basal part; with a row of brownish yellow, thin, posteroventral bristles (two longest ones near middle longer than femur is deep) and a row of pale, short, thin, anteroventral bristles (as long as femur is deep). Fore tibia somewhat swollen in basal part. Mid femur nearly 2.0 times thicker than fore femur; with posteroventral bristles at least as long as femur is deep. Mid tibia with hardly prominent, flattened, apical spur. Hind leg long, slender.

Wing. Slightly infuscate, bearing one short, brownish, basicostal bristle. Vein M1+2 somewhat bowed in apical part but parallel to vein R4+5 near wing-apex. Crossveins m-cu and r-m contiguous. Cell br broader than cell bm. Vein CuA2 somewhat sinuate, recurrent. Vein A1 long. Squama brownish yellow, pale fringed. Halter pale yellow.

Abdomen. With brownish tergites and sternites, shining, clothed with scattered dark setulae. Cerci brown.

Distribution

Thailand.

Remarks

P. seedam sp. nov. should be primarily compared with P. ceylonensis Melander , P. oriens Melander , and P. subulifera (de Meijere) . The original description of P. ceylonensis (known after a female from Ceylon only) is very short and insufficient (Senior- White 1924). Nevertheless, it may be distinguished from the new species by brownish black legs (except for yellowish fore trochanters and extreme tip of coxae). In P. subulifera (known after a female from Java only) the arista is as long as scape, pedicel, and postpedicel combined (versus 1.5 times longer in P. seedam sp. nov.), legs are uniformly brown and halter is brownish, with yellow stem; additionally, this species has two pairs of scutellar bristles ( de Meijere 1914). In P. oriens (known after the type material from Java only), like P. seedam sp. nov., the arista is longer than scape, pedicel, and postpedicel combined, however, the fore femur lacks prominent long bristles in the posteroventral row and the fore tibia is uniformly slender, lacking a basal swelling ( Melander 1928).