Platypalpus fai, 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 : 4036-4038

Platypalpus fai sp. nov. (male)

( Figures 4–6 )

Etymology

The name ‘‘fai’’ refers to the remarkable tubercle bearing hairs on the abdominal sternite 4. ‘‘Fai’’ in Thai means ‘‘tubercle bearing hairs’’.

Diagnosis

Mostly yellow (including legs) species; one pair of short verticals; antenna with scape and pedicel brownish, postpedicel brownish yellow, arista white; postpedicel 3.5 times longer than wide; mesonotum with two large, ovate, brownish spots; thoracic pleura partly brown, legs wholly yellow; abdominal sternite 4 with median brown tubercle bearing tuft of brown setae.

Material examined

Holotype: male, Thailand, Loei province, Na Haeo , FIRS, 11–17 June 2003, Malaise trap (2), leg. P. Grootaert and Siriluck Intarasri.

Male

Body length 3.1 mm; wing length 3.0 mm.

Head. Black in ground-colour. Occiput finely greyish pollinose, subshining, with scattered black bristles in upper part and some pale bristly hairs in lower part, bearing two proclinate, moderately long verticals. Ocellar tubercle with two moderately long bristles. Frons pollinose, mostly very narrow, narrower than anterior ocellus, somewhat widened above. Face concolorous with frons. Antenna with scape and pedicel brownish, postpedicel brownish yellow, arista thick, whitish pubescent. Postpedicel narrow, elongate conical, nearly 3.5 times longer than wide. Arista nearly 3.0 times longer than postpedicel. Palpus wholly yellow, mostly with scattered, short, yellow bristly hairs, bearing one longer, brownish, subapical bristle.

Thorax. Largely yellow; prothoracic notum with brownish spot; prosternum brownish yellow; sutures of prothoracic sclerites brown in varying extent; mesonotum with two rather large, ovate, brownish spots extending from base of scutellum to level of posterior notopleural bristle; mesopleuron yellowish brown posteriorly and narrowly along suture with sternopleuron; sternopleuron almost wholly (except for yellowish brown upper posterior corner) dark brown; hypopleuron largely brown, somewhat paler along border with sternopleuron and in upper part; pteropleuron brownish yellow anteriorly; metapleuron brown; postnotum with brownish metanotum, metapleuron brownish yellow in lower part. Mesonotum and sternopleuron shining, otherwise thorax finely pollinose, subshining. Anterior and posterior spiracles brown. Humerus with one very short, fine bristle and few minute setulae. Mesonotum with two brown notopleural (anterior one shorter and thinner), one postalar (similar to posterior notopleural), and four scutellar (outer ones very short, thin; inner ones longest among mesonotal bristles, cruciate) bristles; some scattered setulae present behind humerus, on notopleural depression, supra-alar space and postalar callus. Acrostichal and dorsocentral bristles yellowish; the former arranged in two regular rows, lacking on prescutellar depression; the latter arranged in one regular row, rather numerous, short, mostly of equal length (except for two pairs of longer prescutellars) and somewhat longer than acrostichals.

Legs. Wholly yellow with some brownish tinge, coxae rather pale yellow. Coxae and trochanters with ordinary yellow to brownish yellow setae. Fore femur slender, with a row of brownish yellow, thin, posteroventral bristles (one longest one near middle of femur longer than femur is deep) and a row of yellowish, short (nearly half as long as femur is deep), thin, anteroventral bristles. Fore tibia mostly slender, somewhat swollen near tibial gland; clothed with ordinary setulae. Fore tarsus slender, unmodified. Mid femur incrassate, nearly 1.5 times broader than fore femur; with rows of ventral black spinules and a row of long (distinctly longer than femur is deep), brown, posteroventral bristles. Mid tibia with black ventral spinules throughout and hardly prominent flattened apical spur. Hind leg long, slender; hind femur somewhat swollen in apical part anteriorly, bearing a row of short, brownish to brownish yellow, erect, antero- and a row of short, pale, posteroventral bristles.

Wing. Slightly infuscate, bearing one long, 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 and with long brownish fringes. Halter pale yellow.

Abdomen. Shining, mostly with distinct brownish yellow setulae; pregenital segments with long bristles. Tergites yellowish brown; sternites mostly concolorous with tergites, sternites 1–2 brown along posterior margin. Sternite 4 with median brown tubercle bearing tuft of short brown setae.

Terminalia. Dark brown, small, subglobular. Left epandrial lamella ( Figure 5 ) pointed toward apex, clothed with long bristles in upper part. Left surstylus small, with several moderately long bristles. Right epandrial lamella ( Figure 6 ) subrectangular, with long bristles in upper part. Right surstylus bilobed. Cerci ( Figure 4 ) digitiform, rather short, left cercus somewhat longer than right cercus, pubescent, with several long bristles. Hypoproct ( Figures 4, 5 ) enlarged but not extending beyond apices of cerci, with two spine-like extensions ventrally.

Female

Unknown.

Distribution

Thailand.

Remarks

P. fai sp. nov. can be readily recognized by its peculiar tubercle on sternite 4 of the abdomen. Besides the feature noted, the new species differs from all species described here (and from P. nepalensis as well) by larger brownish scutal spots extending from base of scutellum to level of posterior notopleural bristle. In P. candidiseta and P. sanguinolentus the mesonotum is wholly yellow ( Bezzi 1912; Brunetti 1913; de Meijere 1914).

Figures

Figures 4–6. Platypalpus fai sp. nov., male. (4) Epandrium with cerci and hypoproct. (5) Left epandrial lamella, left cercus, and hypoproct (lateral view). (6) Right epandrial lamella (lateral view). Scale bar: 0.1 mm.