Platypalpus hualuang, 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 : 4053-4054

Platypalpus hualuang sp. nov. (female)

Etymology

The name ‘‘hualuang’’ refers to the completely yellow head, including the occiput (‘‘hua’’ means ‘‘head’’ while ‘‘see luang’’ means ‘‘yellow colour’’ in Thai).

Diagnosis

Almost wholly yellow species, only mesonotum with narrow, brownish, median vitta and abdominal tergites mainly yellowish brown; two pairs of verticals; antenna pale yellow, postpedicel short, arista 2.0 times longer than postpedicel; acrostichal and dorsocentral bristles multiserial, hardly separated; tarsomeres 3 and 4 of fore tarsus flattened.

Material examined

Holotype: female, Thailand, Loei province, Na Haeo, Chang Tok waterfall, 17 May 2003, sweep netting on vegetation bordering the river Mae Heuang (sample no. 23035), leg. P. Grootaert.

Male

Unknown.

Female

Body length 3.3 mm; wing length 3.1 mm. Head. Wholly yellow in ground-colour (ocellar tubercle with slight brownish tinge). Occiput shining, clothed with rather short bristly hairs, with longer setae in lower part laterally, bearing two pairs of brownish verticals. Ocellar tubercle with two short yellowish bristles. Frons pale yellow, widened toward ocellar tubercle, above antennae about 2.0 times broader than anterior ocellus, pollinose. Face below antennae nearly as broad as frons, partly pollinose, clypeus shining. Antenna wholly pale yellow. Postpedicel conical, rather short, about 2.0 times longer than wide. Arista nearly 2.0 times longer than postpedicel. Palpus wholly yellow, short, ovate, with moderately long subapical bristle. Proboscis yellow, long, almost as long as head is high.

Thorax. Almost wholly yellow; mesonotum with brownish, indistinct, narrow, median vitta (somewhat broader on prescutellar depression). Humerus with one moderately long, brownish bristle and several setulae. Mesonotum with one brownish notopleural, one similar postalar and four scutellars (outer ones very short, inner ones missing). Acrostichals and dorsocentrals mostly very short (except for one pair of long prescutellar dorsocentrals), multiserial, hardly separated, divergent, pale yellow.

Legs. Wholly yellow. Fore femur thickened, with very short antero- and posteroventral bristles. Tarsomeres 3 and 4 of fore tarsus flattened, tarsomere one bearing one long, erect bristle near base. Mid femur incrassate, 1.5 times thicker than fore femur, with two rows of black ventral spinules (posterior ones somewhat longer) and a row of six short, brownish, posteroventral bristles. Mid tibia with short, flattened, apical spur. Hind leg ordinary.

Wing. Hyaline, with yellowish veins, bearing one long basicostal bristle. Veins M1+2 and R4+5 parallel near wing-apex. Crossveins m-cu and r-m contiguous. Squama pale coloured and fringed. Halter pale yellow.

Abdomen. With yellowish brown, shining tergites (except for apical segments) and yellowish sternites; clothed with pale setulae. Cerci largely yellowish, brownish yellow in apical part.

Distribution

Thailand.

Remarks

In having distinct vertical bristles, well-developed humerus, distinct posteroventral bristles on mid femur, polished mesonotum, a hardly prominent spur on the mid tibia, multiserial acrostichal and dorsocentral bristles, a very long proboscis and flattened tarsomeres 3 and 4 of the fore leg, P. hualuang sp. nov. belongs to the P. luteus -group comprising P. luteus (Meigen) , P. pallescens Kovalev , P. stroblii (Mik) (all known from Europe only), P. kurilensis Shamshev (Kuril Islands), and P. longirostris (Bezzi) (Taiwan) ( Bezzi 1912; Chvála 1989; Grootaert and Chvála 1992; Shamshev 1999). The new species can be readily distinguished from P. longirostris , as well as P. longirostris xanthopus (Bezzi) , in the wholly yellow antenna (versus postpedicel wholly black). P. kurilensis differs from P. hualuang sp. nov. by a brownish spot on occiput, shining frons, and black abdomen. Additionally, the new species can be readily distinguished from the European species of this group because P. luteus has one pair of vertical bristles only, P. pallescens has uniformly yellow mesonotum and, finally, P. stroblii possesses a black head.