Vomerina humbug

Winterton, Shaun L., 2007, New species of Acraspisoides Hill & Winterton and Bonjeania Irwin & Lyneborg (Diptera: Therevidae: Agapophytinae), with the description of a new genus, Zootaxa 1438, pp. 1-25 : 22-24

Vomerina humbug gen. et sp. nov.

( Figure 9 )

Type species: Vomerina humbug sp. nov., by present designation.

Holotype male, AUSTRALIA: NEW SOUTH WALES: Tinderry Nature Reserve, Round Flat Fire Trail, 11.2 km E Michelago; across disused track in revegetation site, 19.xii.2004 – 16.i.2005, Malaise, 1186 m, C.L. Lambkin, N. Starick, 35°43’08”S, 149°17’26”E (MEI 165137) ( ANIC).

Paratypes, AUSTRALIA: NEW SOUTH WALES: 8 males, same data as holotype (MEI 165138, 165140-42, 165144-45) ( ANIC), (MEI 165143, 165146) ( QDPI).

Diagnosis. Lower frons and face protruding anteriorly; head and body black with distinct matte whitegrey stripe on pleuron and anterior part of abdomen; elongate velutum patches present on femora; wing cell m3 closed; male genitalia with medial atrium and inner gonocoxal process lacking; ventral lobe plowshareshaped, projecting posteromedially with medial covering of velutum; dorsal apodeme of parameral sheath well sclerotised; ejaculatory apodeme and lateral ejaculatory apodeme short, not greatly elongated or enlarged; gonocoxal apodeme much shorter than gonocoxite length.

Description. Male. Body length: 7.0–8.0 mm.

Head. Frons flat, rugose, much wider than ocellar tubercle at narrowest point, antennal base positioned low on frons; lower frons and face greatly protruding anteriorly ( Fig. 9 A), head glossy black; short, pale setae sparsely distributed on frons, medial stripe of silver pubescence on frons, around antennal bases and along margin of eye, single patch on face extending from margin of eye towards antennal base; ocellar tubercle flat, glossy black with sparse, short dark setae; occiput concave, black, overlain with dense grey pubescence; single row of relatively short, black postocular setae admixed with shorter setae; gena black, overlain with white pubescence admixed with white, elongate setae; palp and labellum brown-black with sparse, dark setae; antenna glossy black, slightly shorter than head; dark setae on scape and pedicel; scape equal to combined pedicel and flagellum length, slightly bulbous, smooth and glabrous, with silver pubescence on medial surface;

Thorax. Black, scutum and scutellum overlain with grey-black pubescence admixed with relatively short, dark setae; scutum patterned thin dorsocentral and medial stripe of pale-grey pubescence, additional pale crescent-shaped markings sometimes present laterally; scutal macrosetae black; pleuron, sternum and coxae glossy black; distinctive broad stripe of grey pubescence along pleuron length; elongate pale setae on anepisternum, katatergite and coxae; legs black with pale setae of various lengths on femora; wing largely hyaline, translucent brown infuscate anteriorly along costal margin, fading to hyaline posteriorly; venation dark; haltere brown; scutal chaetotaxy (pairs): np, 5–6; sa, 1; pa, 1; dc, 1; sc, 1.

Abdomen. Glossy black, uniform scattered pale setae, longer laterally, white-grey pubescence laterally on sternites 1–3.

Male genitalia. Epandrium elongate, slightly tapered posteriorly ( Fig. 9 B), cercus ovate; tergite 8 emarginate medially ( Fig. 9 C); gonocoxite rounded in shape ( Figs 9 D–E), scattered short setae on ventral surface, denser laterally; gonocoxal processes absent; inner gonocoxal process completely absent; gonostylus narrow, apically processes projecting dorsally and laterally; gonocoxal apodeme very short; ventral lobe large, plowshare-shaped, projecting posteroventrally with velutinous pubescence on medial surface of ventral lobe and on ventral surface of gonocoxite; hypandrium relatively large, broadly triangular shaped with rounded corners, barely fused to gonocoxite laterally and overlapping gonocoxite posteriorly; sternite 8 sub-triangularshaped ( Fig. 9 F), setae along entire posterior margin; aedeagus relatively short, distiphallus tapered and upturned slightly towards apex ( Figs 9 G–H); dorsal apodeme of parameral sheath well sclerotised, ‘Y’- shaped; ventral apodeme of parameral sheath relatively short, forked, arms broad apically; lateral ejaculatory apodeme well sclerotised and projecting anteriorly; ejaculatory apodeme length approximately equal to rest of aedeagus, well sclerotised.

Female. Unknown.

Etymology. The generic name is the feminine diminutive of Latin: vomer, plowshare; referring to the distinctive blade shaped ventral lobe of the male genitalia. The specific epithet describes the black and white striped colouration of the body that resembles a humbug , but is also an archaic term (etymology unknown) meaning ‘hoax’ or ‘jest’, referring to the strange male genitalia of this taxon.

Comments. Vomerina humbug gen. et sp. nov. is likely the sister taxon to Bonjeania based on external body shape. The male genitalia of this species are quite different in shape to any other therevid by lacking a medial atrium and inner gonocoxal process, the ventral lobe shape and having a well-sclerotised dorsal apodeme of the parameral sheath. The large, plowshare-shaped ventral lobes are distinctive and observable in undissected specimens. Dramatic reduction of inner gonocoxal processes is found in only one other Australian genus, Actenomeros Winterton & Irwin (Winterton et al. 1999b), where the inner gonocoxal process is reduced but not completely absent as is found in this species. Vomerina humbug gen. et sp. nov. is known only from a series of males from Tinderry Nature Reserve, New South Wales.

Figures

FIGURE 9. Vomerina humbug gen. et sp. nov.: A, male head, lateral view; male genitalia: B, epandrium, dorsal view; C, tergite 8, dorsal view; D, gonocoxite, lateral view; E, gonocoxites, ventral view; F, sternite 8, ventral view; G, aedeagus, lateral view; H, same, dorsal view. Scale line = 0.5 mm.