Ommatomyia cera, Scabrough & Tomasovic, 2010

Scabrough, Aubrey G. & Tomasovic, Guy, 2010, Ommatomyia, a new genus from Vietnam (Diptera: Asilidae: Ommatiinae), Zootaxa 2366 (1), pp. 46-54 : 49-52

Ommatomyia cera sp. nov.

( Figs. 1, 3–12 )

Male. Measurements, body 9.1–11.3 mm; wing 8.0–8.4 mm. Body brown, pleura and legs mostly yellow or brownish-yellow. Head: Brown. Face gently convex, slightly visible in lateral view; FHWR 1.0:9–1.0:12, frontoclypeal suture twice as wide as at antenna and as wide as vertex; yellowish-gray tomentose, slightly more brownish-yellow at antennae; vestiture sparse on dorsal half with scattered short brown setae, setae progressively longer on ventral half, mostly pale; mystax vestiture usually pale, mostly setae and scattered thin bristles medially and laterally below eye; 5-7 additional thin yellowish or brown bristles aligned in two vertical rows, those on ventral half of face longer and slightly thicker. Palpus brown, mostly brown setae, sparse yellow setae basally, apical setae longer and thicker. Proboscis brown, only slightly compressed laterally; setae sparse, yellow. Antenna ( Fig. 1 ) largely brown with brown setae, basal 3 segments brownishyellow, flagellum darker with narrow base paler; stylus dark brown or blackish; pedicel wider apically than flagellum or scape, three-fourths as long as scape, half as long as flagellum; stylus tripartite, basal segment as long as scape, pedicel, and flagellum combined, 2 nd segment contrastingly short, apical segment two-thirds as long as basal segment, with short setae aligned in apposing ventrolateral positions and at slightly different angles; basal setae short, becoming progressively longer apically, those on outer margin slightly longer than those along inner margin. Frons brownish-yellow tomentose, 3-4 short brown setae in single file laterally. Ocellar tubercle normal, visible in lateral view, setae sparse and brown, 2 about as long as scape and pedicel combined. Occiput brown tomentose dorsally, brownish-gray or gray ventrally; vestiture sparse, mostly pale and thin, bristles yellowish, 2-3 postocular bristles strongly proclinate dorsally.

Thorax: Prothorax brownish-yellow or brown, tomentum pale, slightly brownish dorsally, vestiture sparse and pale, 6-8 thin pronotal bristles. Scutum convex, one-third as high as long, with brownish-yellow tomentum dorsally, indistinct stripes medially and crowns of lateral disks slightly darker, paler yellow or gray along margins; vestiture brown, setae sparse and short, mostly limited to acrostichals and above wings; two short, seta-like dorsocentrals posteriorly, four long brown bristles laterally. Scutellum dark, apical margin dull yellow, with brownish-gray tomentum basally, gray apically, and sparse brown or yellowish setae; two dark marginal bristles and prominent preapical groove. Mediotergite entirely black, or with brownish-yellow stripe medially, tomentum brownish-gray. Anatergite brownish-yellow or blackish, tomentum yellowish-gray or gray, without setae. Pleuron dull brownish-yellow or yellow, anepisternum brown dorsally; tomentum yellowish-gray or gray, vestiture mostly yellowish, one metakatepisternal and 2-5 katatergal bristles long and brown; anepimeral bristle absent. Halter dull yellow, base and club narrowly sooty, brown or blackish. Metacoxa sclerotized, wide blackish triangle medially, yellow laterally.

Wing ( Fig. 3 ): Surface pale yellowish or brown, apical one-third and narrow posterior margin microtrichose, bare elsewhere. Cell r 1 closed with veins R 1 and R 2+3 fused before costa. Cell r 4 triangular with narrow base, short with base well beyond cell d. Cell m 1 narrow basally, m 1 WR=1.0: 2.0:2.0. Crossvein r-m at apical two-fifths of cell d; vein R 4+5 abruptly angled at junction with R 2+3. Cell m 3 three-fourths as long as d, with M 3 arched, m-cu short.

Legs: Legs slender, yellow. Femora with narrow brown preapical bands, faint on fore femur, darker and wider on middle and hind femora; narrow apices of hind tibia and basal four tarsomeres narrowly, and apical tarsomere entirely brown; HFWR 1.0:8.0. Short setae brown, longer setae and bristles yellow, usually one brown bristle on middle and hind femora anteriorly; ventral bristles long, seta-like. Fore and middle tibiae with sparse, unusually long, yellow bristles laterally, longest bristle half as long as each tibia, apical bristles brown; apical half of hind tibia with only shorter, thicker brown bristles. Basal tarsomere of hind tarsus as long as apical four tarsomeres combined; basal two, sometimes three, tarsomeres yellow, narrow apices brown; tarsomeres otherwise mostly or entirely brownish-yellow or brown; basal tarsomeres of fore and middle tarsi with 1–2 yellow bristles, tarsal bristles long and thin, usually brown. Pretarsus normal, pulvilli brownish-yellow, claws black, narrow base reddish or brownish-yellow, empodium yellow, seta-like, as long as claws.

Abdomen: Brown, narrow apical margins and apical corners of tergites 1–5 yellowish; sternites 1–4 brownish-yellow; tomentum dense brownish-yellow on segments 1–2 and sternites 3–7, brown on tergites 3– 7 dorsally, sparse or absent on segment 8 except dense on apical margin narrowly. Sternite 7 with deep ‘V’- shaped notch basally. Setae short and mostly brown dorsally, longer and yellow on segments 1–2 laterally and sternites 3–7; bristles thin, often seta-like, and yellow on sternites and apical margin of tergites.

Terminalia ( Figs. 4–8 ): Brown with mostly brown setae; cercus yellow, small only slightly visible, ventral lamella erect, wider than paired cerci, apical margin convex in dorsal view. Epandrium wide, concealing dorsal and lateral surfaces of terminalia, narrowed and abruptly angled 90 o medially, rotated horizontally toward opposing epandrium; flat, wide, and lobed apically with 3 long denticles. Gonostylus stout, horizontally flat, apex wide, apical margin truncate. Gonocoxite with long ventral finger and shorter dorsal thumb-like processes, apex at or just beyond epandrium apically. Aedeagus with short swollen distiphallus, epiphallus absent, one posteroventral aedeagal apodeme. Hypandrium wider than long, apical margin truncate, slightly depressed medially.

Female. Measurements, body 10.0-10.5 mm; wing 9.3-9.4 mm. Head: Yellow or brownish-yellow tomentose. Facial brown, setae sparser and shorter ventrally than in male; epistome twice as wide as face at antennae and at vertex. Flagellum yellow, apex brown, slightly shorter than scape; FHWR 1.0:8.3. Thorax: Pleural bristles brown. Wing: As male. Legs: Middle and hind femora with anterior and anteroventral all or most brown; hind tibia with sparse yellow and brown bristles. Abdomen: Sternites with mixed yellow and brown or only brown setae. Terminalia ( Figs. 9-12 ): Tergite 9 about as long as cercus. Sternite 8 much longer than wide, apical third somewhat membranous medially; lateral margin sclerotized, somewhat raised, and digitate with stout internal apodeme paralleling inner margin, digitate margin sometimes slightly over-lapping membranous area. Genital fork mostly membranous, base wide and short, dorsal half of each arm sclerotized. Three spermathecae filamentous, extremely narrow, without prominent apical capsules and basal valve; each spermatheca joins bursa complex separately.

Types. [South Central] VIETNAM / Lam Dong [Province], Bidoup Nuibar [Nuiba National Park] / nr. Dalat 1680-1700 m. / Malaise Trap 19–23 / 12-15.x.2005 Leg C. / Van Achterberg & R. de Vries (holotype m, RMNH) . Paratypes, same data as holotype except Malaise Trap 1–12 [primary] rain forest / & Pinus [kesiya trees] (2 ♂, 2 ♀, RMNH; 2 ♂, 2 ♀, USNM; 14 ♂, 15 ♀, IRSNB) .

Etymology. Gr. keraia for antenna, referring to the form of the antennal stylus.

Remarks. In addition to the diagnostic characters of the genus above, the prominent angular base of R 4+5, base of r 4 well beyond discal cell ( Fig. 3 ), the absence of anepimeral bristles, prominent scutellar groove, and combined characters of the terminalia ( Figs. 4–12 ) distinguish Ommatomyia cera gen. et sp. nov. from all members of Ommatiinae .

Figures

FIGURES 1–3. Ommatiinae antennae & wing. 1. Ommatomyia cera gen. et sp. nov., antenna; 2. Ommatius anisoramus Scarbrough & Hill, 2000a, antenna; 3. Ommatomyia cera, sp. nov., wing. Abbr. flgm=flagellum, ped=pedicel, scp= scape, vein R4+5, cells m3, r4.

FIGURES 4–8. Male terminalia, Ommatomyia cera gen. et sp. nov., 4–6. Dorsal, lateral, & ventral views; 7. Gonostylus; 8. Aedeagus. Abbreviations: aed= aedeagus, aed apod= aedeagal apodeme, aed sh=aedeagal sheath, cerc= cercus, epand=epandrium, ej apod= ejaculatory apodeme, goncx= gonocoxite, gonst= gonostylus, hypd= hypandrium, st7= sternite 7, vl =ventral lamella.

FIGURES 9–12. Male terminalia, Ommatomyia cera gen. et sp. nov., 4–6. Dorsal, lateral, & ventral views; 7. Gonostylus; 8. Aedeagus. Abbreviations: aed= aedeagus, aed apod= aedeagal apodeme, aed sh=aedeagal sheath, cerc= cercus, epand=epandrium, ej apod= ejaculatory apodeme, goncx= gonocoxite, gonst= gonostylus, hypd= hypandrium, st7= sternite 7, vl =ventral lamella.