Ceratomerus falcatus, Bradley J Sinclair, 2003

Bradley J Sinclair, 2003, Taxonomy, Phylogeny and Zoogeography of the Subfamily Ceratomerinae of Australia (Diptera: Empidoidea), Records of the Australian Museum 55, pp. 1-44 : 27-29

Ceratomerus falcatus n.sp.

Figs. 70, 76, 77, 80, 91, 92

Type material. HOLOTYPE 3, “ AUST [ralia]: QLD [Queensland]: Lamington/ N.P., Green Mtns./ 6.v.1994, Elabana Falls/ B.J. Sinclair / ex. Canungra Ck.”; “ HOLOTYPE / Ceratomerus / falcatus / Sinclair [red label]” AMS K175249 . P ARATYPES: New South Wales: 13, Barrington Tops NP, Gloucester Tops, 1200 m, Nothofagus , str., 21.xii.1993, BJS ( ZFMK); 13, Barrington Tops NP, Williams R., subtrop. rainfor., 19– 20.xii.1993, DJB ( AMS); 3833, 2♀♀, Barrington Tops NP, Williams R., subtrop. rainfor., 480 m, 19.xii.1993, 21.i.1995, BJS ( AMS, CNC); 733, 3♀♀, 23 km WNW Bellangry, Cockerawombeeba Ck, warm temp. rainfor., 730 m, 8.xii.1986, 14–15.i.1988, DJB ( AMS); 26 33, Border Ranges NP, Brindle Ck, 1000 m, rainfor., 25–26.i.1995, BJS ( ANIC, CNC, ZFMK); 233, Chichester SF, Allyn R., 22.i.1995, BJS; 1♀, Dorrigo NP, 2–15.x.1984, MT, I. Naumann, J. Cardale ( ANIC); 5 33, 1♀, Dorrigo NP, Rosewood Ck, 23.i.1995, BJS ( CNC); 533, 1♀, Dorrigo NP, Sassafras Ck 700 m, Callicoma Falls, subtrop. rainfor., 1.iv.1995, BJS ( ZFMK); 333, Mt. Hyland NP, Obeloe Ck, 1030 m, 30°10'S 152°27'E, y.pans, warm temp rainfor., 25–27.i.1996, DJB; 1 3, Werrikimbe NP, N. Plateau Beech For., y.pans, 28.xii.1993, DJB; 533, 9♀♀, Upper Allyn R., nr Eccleston, 4.v.1967, DKM ( AMS). Queensland: 1033, 1♀, same data as holotype ( AMS, CNC).

Additional material (in alc.). New South Wales :13, 3♀♀, New England NP, Point Lookout, 30°29'S 152°25'E, 12.ii.1984, I.D. Naumann ( ANIC) .

Diagnosis. Distinguished from other members of this species group by the simple male wings, with straight veins and lacking spots, and the auxiliary crossvein is present in both sexes. Females are generally difficult to separate from C. maculatus , but sometimes distinguished by their more lightly infuscate wings and the radial fork is generally proximal to cell dm.

Description. Wing length 2.1–2.3 mm.

Male. Head ( Fig. 91) dark brown, dull; face pale brown, lacking setae; ocellar triangle with 2 widely spaced, divergent bristles, inserted anterior to lateral ocelli; postocellar bristle long, two-thirds to subequal to length of ocellar bristle; 2 pairs of long vertical bristles; postocular bristles long, overlapping one-third of eye. Antenna with scape two-thirds height of eye, with 3–4 dorsal setae and 1 long ventral seta; pedicel cylindrical, slightly greater than half length of scape; setae confined to apical fringe. Postpedicel covered by long, dense pruinescence, less than 1.5× height of head; basal half rectangular; apical half narrow, nearly parallel-sided, not strongly tapered; threesegmented stylus one-fourth length of postpedicel; segment 8 short, width subequal to length; stylus concolorous with remaining segments. Base of labrum lacking dorsal process; palpus yellowish-brown, slender, one-sixth length of labrum, with several dark setae; prementum with short setae only.

Thorax. Scutum and postnotum dark brown; pleura brown, darker along dorsal margin; postpronotal lobe brown; scutum lacking vitta of pruinescence. Alternating row of short acrostichals to prescutellar depression, subequal in length, directed posteriorly; 4 dc, third dc short and slender; 1 pprn; 1 presut spal; 2 npl, lower weak; 2 psut spal; 1 pal; 4 sctl, outer pair short, slender; additional setulae lacking. Antepronotum lacking setulae.

Wing ( Fig. 80) infuscate, stigma lacking; single short costal seta; costal margin with unmodified setulae; posterior margin lacking incision; posterior setal margin complete, unmodified. R 2+3 gradually arched to C, not deflected; radial fork bellshaped; medial fork distal to radial fork; cell dm rectangular, slender; auxiliary crossvein between R 2+3 and R 4 (occasionally absent on one wing). Halter with pale brown knob.

Legs. Coxae yellowish brown, remaining leg segments brown, darker towards tip. Fore coxa about twice length of mid coxa, with long dark anterior setae. Fore trochanter lacking modified setae. Fore femora slightly swollen, with av row of dark setulae; pv region with 2 basal setulae. Fore tibia slightly shorter than femur; apex with anteroapical comb, not dilated. First tarsomere greater than half length of fore tibia; tarsomeres 1–3 slender, tarsomeres 4 and 5 dorsoventrally flattened.

Mid coxa lacking modified seta. Mid femur slender with unmodified setae.Mid tibia subequal in length to femur; lacking erect setae. First tarsomere equal in length to remaining 4 tarsomeres; tarsomere 5 dorsoventrally flattened.

Hind coxa with unmodified setae. Hind femur straight with 1 preapical dorsal seta. Hind tibia straight, shorter than femur, apex dilated, bearing posteroapical comb; pv surface lacking setae. Hind tarsomeres longer than tibia; first tarsomere with 1 short, erect ventral seta near base; tarsomere 5 dorsoventrally flattened.

Abdomen pale brown, sclerites thinly sclerotized, posteromarginal setae short, longest on T6; sclerites lacking ridges and modified setae; central region of T7 membranous; S7 slightly longer than preceding sclerite, lacking posterolateral extension; T8 slender, with broad rectangular posterior membranous zone.

Terminalia ( Figs. 76, 77, 92). Hypandrium with short posterior flap-like process; 2 pairs of sickle-shaped, articulated postgonites flanking phallus, outer pair shorter, strongly recurved, inner pair long, slender. Phallus comprises single, straight, pointed median process. Apical corner of epandrial lamella narrow; posterior margin with long setae along inner posterior margin. Surstylus weakly developed, with only partial subapical weakening on epandrium. Cercus thinly sclerotized, short, apex blunt, expanded laterally around anus.

Female. Similar to male except as follows: pedicel slightly greater than half length of scape; palpus brown; setae and modifications of legs lacking; pleura brown. Apical segments retracted into segment 7; apical margin of segment 7 not folded inwards; T7 lacking posterior fringe of setae; lateral margin of S7 straight. Terminalia: central region of T8 with deep U-shaped weakly sclerotized zone; fringe of long setae along lateral ridge; anterior margin with broad, flattened, median process, extending beneath T7 when segment retracted; S8 the posterior margin invaginated, forming internal flooring. T10 split medially into pair of rectangular sclerites; anterior margin with stout, straight, spine-like setae; cercus with terminal cluster of 4–5 spinelike setae, similar to T10. Spermathecal receptacle spherical, with short neck where duct attached.

Distribution. This species is distributed from the Border Ranges at the New South Wales and Queensland border, south to Barrington Tops at elevations generally above 400 m ( Fig. 70).

Etymology. The specific name is from the Latin falcatus (sickle-shaped), referring to the shape of the male postgonites.