Platypalpus syletor (Melander) Melander, 2012

Shamshev, Igor & Grootaert, Patrick, 2012, Proposed change in status of the Nearctic genus Charadrodromia Melander (Diptera: Hybotidae, Tachydromiinae), with description of four new species, Zootaxa 3525, pp. 35-50 : 40-41

Platypalpus syletor (Melander) comb. nov.

( Figs. 7–11 )

Charadrodromia syletor Melander, 1928: 293 . Type locality: Adna, Washington ( USA).

Type material examined. HOLOTYPE, Ƥ labelled: Adna / Wash. [Washington]; July 10, 1917; A.L. Melander. AL Melander / Collection / 1961. TYPE / Charadrodromia / syletor / Mel. [Melander] [red label, hand-written] ( USNM).

Additional material examined. USA. California: 2 3, 1 Ƥ, Mendocino Co., Mendocino Nat. For., Buck Rock Cr. at rd. # lN02, 20.vi.1976, D.D. Wilder ( CAS).

Recognition. This species is distinguished by two pairs of vertical bristles; antenna brown, postpedicel short; palpus brown; scutum finely greyish tomentose, entire mesopleuron densely greyish tomentose; legs brown, mid tibia without apical spur.

Re-description. Length: body 1.9 mm, wing 2.2 mm. Male (described for the first time). Head black in ground-colour. Frons broad, densely light grey pollinose, widened toward ocellar tubercle. Face narrow, concolorous with frons. Ocellar tubercle with 2 long brown proclinate anterior and 2 short lateroclinate posterior bristles. Two pairs of long brown verticals. Occiput greyish pollinose, with numerous thin yellow to pale setae of different lengths. Antenna brown; postpedicel almost drop-like, short, about 1.5X as long as wide; stylus nearly 4.0X as long as postpedicel. Proboscis short, brown. Palpus small, brown, pale pubescent, with several pale setae of different lengths.

Thorax black in ground-colour, postpronotal lobe and scutum rather subshining, finely greyish tomentose, proepisternum and entire mesopleuron densely greyish tomentose, katepisternum without shining spot; larger bristles brown. Postpronotal lobe subglobular, rather large, with 1 long inclinate bristle and several short yellowish to pale setae. Mesonotum with 2 notopleurals, 1 postalar and 4 scutellar bristles (apical pair very long and inclinate, lateral pair very short); additionally, notopleural depression with several minute setulae and similar setulae present behind postpronotal lobe and on postsutural supra-alar space; dorsocentrals arranged in 3 irregular rows anteriorly, otherwise 1–2-serial, short, 2 prescutellars long; acrostichals arranged in 2 irregular rows, short.

Legs brown, only knees of fore leg somewhat paler; mostly with pale to yellow setation. Fore femur distinctly thickened, covered with short setae. Fore tibia spindle-shaped. Mid femur narrower than fore femur; with anteroventral and posteroventral setae longer basally. Mid tibia without apical spur, with erect spinule-like setae ventrally. Hind femur with short anteroventral setae. Hind tibia unmodified, covered with short setae.

Wing finely brownish infuscate, with brownish yellow veins. One long brown costal bristle. Veins R4+5 and M straight and parallel near wing margin; CuA2 sinuous; cells br and bm contiguous, bm broader than br. Squama brown, with pale setae. Halter yellow.

Abdomen brown in ground-colour, almost entirely shining, only tergite 1 finely greyish pollinose laterally; with pale setation longer on pregenital segments. Terminalia ( Figs. 7–10 ) moderately large, concolorous with abdomen; left cercus digitiform, rather long, nearly as long as left cercus, with short unmodified setae; right cercus digitiform, narrow than left cercus, with short unmodified setae; left epandrial lamella rather subtriangular, broad, with short setae along ventral margin; right epandrial lamella elongate oval, with several long setae apically; right surstylus undifferentiated from epandrium, bilobed, bearing short unmodified setae.

Female ( Fig. 11 ). Mid tibia with unmodified setulae ventrally. Abdominal segments 7–8 densely greyish pollinose; covered with scattered short pale to brownish yellow setulae; cercus brown elongate. Distribution. USA (California, Washington).

Remarks. The species was described originally from a single female. The holotype is in very good condition. Platypalpus syletor can be readily distinguished from the Nearctic species of the P. hackmani group by brown legs.

Figures

FIGURES 7 – 11. Platypalpus syletor (Melander). 7. apical part of right epandrial lamella, ventral view. 8. right epandrial lamella, lateral view. 9. cerci and epandrium, dorsal view. 10. left epandrial lamella, lateral view. 11. habitus, female (holotype), lateral view.