Anabarhynchus oblongicornus, Winterton, 2004

Winterton, Shaun L., 2004, Are hind coxal knobs a synapomorphy for therevids? An unusual new species of Anabarhynchus Macquart from Australia (Diptera: Therevidae: Therevinae), Zootaxa 413 (1), pp. 1-8 : 3-7

Anabarhynchus oblongicornus sp. nov.

( Figs 1 , 2 )

Holotype male, AUSTRALIA: Queensland: Great Sandy National Park, Cooloola Section , 25° 57 15 S 153° 06 27E, 1­5.x.1996, D. Yeates, C. Lambkin, S. Winterton ( MEI#091215 ) ( ANIC).

Paratypes: AUSTRALIA: Queensland: 2 males, 2 females, same data as holotype ( MEI#091212­14 , 091216 ) ( ANIC) ; 1 female, same data has holotype except: 25° 53 31 S 153° 05 06E ( MEI#091210 ) ( ANIC) ; 1 male, 1 female, same data as holotype except: 25° 53 31 S 153° 05 06E ( MEI#091209 , 091211 ) ( QMBA) ; 1 female, same data as holotype except: 26° 01 37 S 153° 05 33E, malaise trap ( MEI#091208 ) ( QMBA) ; 1 female, Rainbow Beach , 05.x.1996, on fore dune, S. Winterton, hand collected ( MEI#091217 ) ( QMBA) .

Etymology. The specific epithet is derived from the Latin: oblongus, longer than broad, and cornu, horn; referring to the distinctively elongate antennae found in this species. Gender is neuter.

Diagnosis. Autapomorphies: scape longer than head, flagellum elongate, hind coxal knob absent, apex of distiphallus with large articulated spines. Shared characters (with some Anabarhynchus species ): costal setae arranged in two rows, prosternal pile absent, hypopleural pile absent, fore femur with 1­2 posterodorsal setae, epandrium narrowed posteriorly.

Description: Male. Body length: ca. 6­8 mm. Head. Frons wider than ocellar tubercle at narrowest point, antennal base positioned low on frons; frons flat, glossy black, overlain with silver­grey velutum pruinescence pattern as in figure 1B; lower frons and face overlain with silver pruinescence; ocellar tubercle black with sparse grey pruinescence; occiput convex, covered with dense silver­white velutum pruinescence, when viewed from nonreflective angle velutum pruinescence is black to bronze laterally on medial occipital sclerite above occipital foramen, occiput with broad margin of silver velutum; 2­3 poorly defined rows of black postocular setae; gena black, densely overlain with silver­white velutum pruinescence admixed with long, pale setae; palp and labellum dark yellow with scattered pale setae; antennae elongate ( Fig. 1A ), longer than head, short, dark setae on all segments; scape length equal to head, dark yellow basally to brown distally; pedicel and flagellum black or dark brown; flagellum elongate, approximately half length of scape. Thorax. Scutum glossy black, overlain with alternating stripes of gold­brown and whitegrey pruinescence sparsely admixed with short, pale setae; scutellum glossy black and overlain with grey pruinescence, scutal macrosetae (bristles) dark; pleuron and coxae glossy dark brown­black, overlain with sparse to dense silver velutum pruinescence except on anterior surface of anepisternum, hypopleural pile absent; pale setae on anterior surfaces of fore and mid coxae and on posterolateral surface of hind coxa, macrosetae pale; legs yellow, fore tibia, fore tarsi and apex of fore femur darkened, fore femur with one to two dark posterodorsal setae, hind femur with single dark seta apically; wing hyaline, tinted uniformly brown, venation dark; halter yellow, stem darkened; scutal chaetotaxy (pairs): np, 3­5; sa, 2; pa, 1; dc, 3; sc, 2. Abdomen. Black with scattered pale setae, longer laterally, posterior margins with white band; bright silver velutum pruinescence on segments 1­5, extensive on segments 1­3 and present laterally on segments 4­5 posteriorly; tergites 2­6 overlain with thin silver­grey velutum; tergites 2­3 with bronze velutum dorsally. Genitalia. Epandrium ( Figs 2 A­B) slightly longer than wide, narrowed posteriorly; tergite 8 band like, only slightly expanded laterally ( Fig. 2D ), irregular row of dark elongate setae along entire posterior margin, spiracular pore near anterior margin; hypandrium apparently absent; gonocoxites ( Figs 2C , E­F) semi­spherical, separate ventrally, extended slightly into rounded processes posteroventrally [? = outer gonocoxal process], numerous elongate setae along posterior surface, darker laterally; gonocoxal apodeme reduced, weakly sclerotised; inner gonocoxal process shorter than gonostylus, apex bilobate; gonostylus elongate, as long as gonocoxite, rounded process midway along dorsolateral surface, apex truncated, slightly reflexed dorsally, numerous pale elongate setae on medial surface; ventral lobe absent; parameral sheath dark sclerotised ( Figs 2 G­H), distiphallus strongly curved ventrally at base, rounded bulbs on either side of base, distiphallus expanded slightly apically, apex open, ringed with strong setae, aedeagus evident internally, narrow, extending beyond end of distiphallus; dorsal apodeme of parameral sheath triangular, covering ejaculatory apodeme dorsally; ventral apodeme quadrangular, lateral ejaculatory apodeme narrow, band­like, ejaculatory apodeme narrow, barely extending beyond dorsal apodeme.

Female. Similar to male except: Uppers frons with bronze velutum pruinescence; abdomen without silver velutum pruinescence. Genitalia. Tergite 8 with narrow anterior marginal process; sternite 8 ( Fig. 2I ) emarginate posterolaterally, inverted melanised chevron posteriorly; spermathecal sac elongate ( Fig. 2J ), narrowed distally; spermathecal sac duct relatively short, spermathecal duct joined to spermathecal sac duct proximal to furca; accessory gland elongate, two spermathecae, non­spherical.

Comments. Anabarhynchus oblongicornus sp. nov. is closely related to A. maritimus Hardy. Both species are the only members of Anabarhynchus that lack hypopleural pile, and both are beach fore­dune inhabitants. Anabarhynchus oblongicornus sp. nov. keys out to A. maritimus in the key presented in Lyneborg (2001), and can be quickly separated from A. maritimus by the presence of elongate antennae, hyaline wings and white­grey stripes on the scutum of A. oblongicornus . Anabarhynchus oblongicornus is known from a single series of specimens collected near Rainbow Beach, Great Sandy National Park, southeastern Queensland, Australia.

The elongate antennae and lack of hind coxal knob quickly differentiates A. oblongicornus sp. nov. from all other Anabarhynchus species. The absence of a hind coxal knob is rare in therevids. The hind coxal knob is always present in Agapophytinae and the Taenogera genus­group, but appears to be secondarily reduced or absent in certain therevine and phycine genera. The hind coxal knob is missing in all species of the genus Actorthia Kröber (Phycinae) , a genus found from North Africa to Central Asia. Within Therevinae , the hind coxal knob is completely absent in the genera Ammonaios Irwin and Lyneborg and Arenigena Irwin and Lyneborg (both southwestern Nearctic) and is reduced in Pseudothereva parviseta Lyneborg ( South Africa) and some species of Ammothereva Lyneborg (Asia) (Anon. pers com., M. Metz pers. com.). Yeates (1994) used the presence of the hind coxal knob as a synapomorphy for Therevidae , and later ( Yeates 2002) as a synapomorphy for Therevidae + Apsilocephalidae , but as more genera are surveyed it appears that the hind coxal knob is absent in some therevids. Moreover, Metz (2003) found the hind coxal knob is present in the basal scenopinid genus Caenotus Cole ( Metz 2003) . Rather than apomorphic for Therevidae + Apsilocephalidae , the hind coxal knob appears to be plesiomorphic for the entire therevoid clade ( Apsilocephalidae + Scenopinidae + Therevidae ) and secondarily reduced or absent in all higher scenopinids (i.e. Proratinae + Scenopininae ) and several distantly related species of Therevidae .

Figures

FIGURE 1. Anabarhynchus oblongicornus sp. nov., A, male head, lateral; B, frontal. Scale line= 0.5 mm.

FIGURE 2. Anabarhynchus oblongicornus sp. nov., terminalia. Male: A, epandrium; B, same lateral; C, gonocoxites, ventral; D, tergite 8, lateral; E, gonocoxites, lateral; F, same, dorsal; G, aedeagus, dorsal; H, same, lateral. Female: I, sternite 8, ventral; J, distal reproductive complex. Scale line= 0.2 mm.