Oxycanus petalous Beaver & Moore, 2020

Beaver, Ethan P., Moore, Michael D., Velasco-Castrillón, Alejandro & Stevens, Mark I., 2020, Three new ghost moths of the genus Oxycanus Walker, 1856 from Australia (Lepidoptera: Hepialidae), Zootaxa 4732 (3), pp. 351-374 : 358-365

Oxycanus petalous Beaver & Moore , sp. nov.

( Figs 2 A–B; 3G–H; 6A–C; 7F; 8C, 9A–B; 10C)

Type specimens: Holotype male, WAM . Paratypes: 28 males and 9 females, SAMA, ANIC .

Type locality: Boxwood Hill , Chingarrup, South Coast, Western Australia, Australia .

Etymology. The name ‘ petalous’ is from the Greek petalo (πέταΛΟ) which translates to ‘horseshoe’ and is in reference to the horseshoe-shaped eighth sternite (S8) of the male.

Type material. HOLOTYPE. (In WAM) ♂. West Aust. , South Coast , Chingarrup, Boxwood Hill, 34°20’46”S, 118°43’51”E, M. Moore, 1st May [20]17 / SAMA Database no. 31-020332 / spec. no. 17123 leg removed for tissue storage MD Moore . PARATYPES. 37 specimens: 9 ♀, 28 ♂. 1 ♂, Boxwood Hill , 34°18’17”S, 118°43’43”E, M. Heath, 25th April 2015 / SAMA Database no. 31-019833 / spec. no. 19024 . 1 ♂, 1♀, West Aust., Boxwood Hill , 34°18’17”S, 118 43’43”E, Mark Heath; 25th April 2015 / SAMA Database no. 31-019832 / spec. no. 19025 leg removed for tissue storage MD Moore / MH 5 ; male with SAMA Database no. 31-019831 . 2 ♀, March 2015, Gleneagles Rest Area, Western Aust. , 32°18’3” S 116°12’3” E, P. Kay / spec. no. 128 leg removed for tissue storage MD Moore / SAMA Database No. 31-019829; second specimen with SAMA Database No. 31-019830 and spec. no. 129; (all in SAMA) . 1 ♂ 22–23 April 2000, nr. Mt Barker, Western Australia, 34.41.404S, 117.47.374E, M. Court, to light trap, Eucalyptus globulus plantation #1, 3 / Barcode of life DNA voucher specimen sample ID: 10ANIC-09486, BOLD proc. ID: ANICM489-10 / Dissection ID EPB-ANIC-1. An additional 2 ♀ and 2 ♂ with the same data, except ANIC no 31-036828-31-036829 for the females and 31-036810, 31-036812 for the males. An additional 16 ♂, 3 ♀, same data except the date 20–21 April 2000, females with ANIC no’s 31-036830 to 31-036832, males with ANIC no’s 31-036809, 31-036811, 31-036814 to 31-036827. 1 additional ♀, same data except dissection ID EPB-ANIC-2 . 1 ♂, same data except 19-20 April 2000, ANIC no. 31-036813 . 2 ♂, Peak Charles NP, WA, Aust. , 32°53’56.4”S 121°11’01.0”E, 16 April 2007, MV lamp and UV-fit, A. Zwick and G. Cocking / Dissection ID EPB- ANIC-8 and EPB-ANIC-14 . 1 ♂, Stirling Range, WA, 26 Mar 1968, I.F.B. Common & M.S. Upton / Dissection ID EPB-ANIC-7, ANIC no. 31-036833 . 3 ♂, Stirling Range Nat. Park , WA, 34.23S 118.07E, 17 April 1983, I.F.B. E.S. Nielsen & E.D. Edwards, ANIC no. 31-036834-31-036836 (all in ANIC) .

Distribution. All specimens taken from the far south of Western Australia, from Mount Barker; Gleneagles Rest Area ( Fig. 15 ); Stirling Range NP; Boxwood Hill; and Peak Charles ( Fig. 11 ).

Diagnosis. This species falls within a small ‘WA species group’, a group distinguished from other Western Australian species by the presence of para-anal sclerites in the male genitalia. The sclerotised horseshoe shaped sternum 8 distinguishes males from the trapezoidal sternum 8 of O. determinata ( Figs 2 C–D, 3E–F, 6D–F, 7C, 8F, 9C–D) and O. kochi . Sternum 8 in O. glauteri is less distinctly curved ( Tindale 1955: figure 23), while the pseudotegumen differs markedly particularly in the shape of the dorso-posterior margin of the pseudotegumen which bears a distinct vertical spine absent in O. petalous sp. nov. The pseudotegumen of O. petalous sp. nov. has a small spine 1/3 rd the length from the proximal end, a large medial spine, and a larger broadly triangular spine basally towards the vinculum ( Fig. 7F ). It also has relatively greater fusion at the apex of the pseudoteguminal arms. The females can only be reliably differentiated from O. determinata by examination of genitalia characters ( Figs 9 A–B). In O. petalous sp. nov. the dorsal plate is strongly arched and has posterior, elongated finger-like projections. The sub-anal sclerite is rectangular when viewed postero-ventrally. The lateral lobe of the antevaginal lamella is narrower, with a subtriangular base and is setose only at the distal end whereas in O. determinata it is mostly setose. The forewing apex is slightly rounder than in O. determinata .

Description. Male ( Fig. 2A ) Head: Antennae ( Figs 3 G–H), 9 mm, 53 flagellomeres, to basal area of costa, yellow, weakly bipectinate giving a general filiform appearance, primary rami very short and flattened, ciliated, ridge present, ciliated, proximal bar absent. Scape elongate, cylindrical; pedicel ovoid, flattened. Eyes larger than twice width of head, scales on frons and vertex dense, dark brown to black coloured. Palps long, half length of head, three segmented, directed forward, second longer than third, with first palpomere shortest; club-shaped distal palpomere.

Thorax: pro- and mesothorax covered in dark grey, brown, black densely layered scales, darker on ventral surface. Legs dark brown, densely scaled, epiphysis present, slightly longer than wide, triangular. Fore- and mid legs dark, hind legs covered with bright yellow scales. Wings: FW: 25–27 mm, expanse 60 mm, elongate, broadly triangular. Costa slightly concave centrally, convex towards apex. Apex pointed. Wing venation classically oxycanine ( Fig. 10C ), vein 2A extends to margin, short. HW: 20–21 mm, elongate, similar shape as forewing but slightly short- er, with sharper termen, CuP partially membranous medially. Dorsal FW ground colour dark brown or brownishgrey, darker along costa and apex, basal area buff-grey. Lighter brown scales interspersed with darker scales across entire wing surface. Small, angled cream bar across posterior end of discal cell in some specimens. Some specimens with small triangular white spots in sub-marginal area between Rs4 and M 2. Some specimens have a diverse range of small rounded or trapezoidal white spots. Veins with darker scales than general wing surface, latter less densely scaled. Outer margin with fringe of longer, pale brown scales. Ventral surface as above with piliform scales on basal and costal areas, the latter lighter brown, lacking white spots. HW dorsal surface yellow or light brown, unmarked. Basal area semi-translucent, finely covered with long piliform scales of same ground colour.Apex dark brown, wing veins Rs1 to Rs3 covered in dark brown scales, others with yellow scales. Fringe dark brown, becoming yellow towards tornus. Ventral surface as above or with bottom half of wing entirely buff or yellow, with greater extent of piliform scales, veins edged with yellow scales.

Abdomen: Narrow, tapering, first 3–4 tergites covered with mustard-yellow to cinnamon brown coloured scales on all surfaces, brown on posterior tergites. Sternum 8 horseshoe shaped, highly sclerotized, more than all other sternites, anterior corners rounded, posterior corners acute. Sternum 8 unfused from apodemal vinculum, setose at posterior margin.

Genitalia ( Figs 6 A–C, 7F, dis. no. 31-019833; dis. no. EPB-ANIC-1). Pseudotegumen: basal rim broad and rounded, centrally depressed with margin upturned. Dorso-distal twin processes heavily sclerotized, elongate, leaf shaped, and with apex rounded and cupped; in lateral view a deep groove is present, otherwise smooth; dorso-posterior margin membranous, disto-posterior margin finely serrated, coming to a sharply acuminate point at apex. Ventro- and disto-posterior margins are highly sclerotized in lateral view, broad and convex, with a small spine 1/3 rd along margin, larger spine medially, and a larger triangular spine basally towards vinculum. Ventral pseudoteguminal arms indistinct, lobes fused across median. Valvae: long, narrow, distally lobate with long setae, flattened laterally with deep, triangular sacculus. Distally shorter than disto-posterior margin of pseudotegumen when in habitus position. Para-anal sclerite very large relative to pseudotegumen, elongate, upright, base large, sub-triangular, with ventral-oriented projection, apex club-shaped and curving laterally, becoming membranous along proximal rim, positioned well back between disto-posterior margin of pseudotegumen and dorso-distal twin processes which also curve back. Apodemal vinculum narrow, generally triangular; dorso-posterior arms deep, in lateral view anterior end broad. Saccus broad, sclerotized, generally triangular and large, bilobed posterior-central margin, dorso-posterior arms narrow, sclerotised, ventrally-oriented, membranous at end of dorso-posterior arms, where membrane puckers and folds outwards as a fringe, in lateral view anterior end bulbous. Juxta trapezoidal, concave; anterior margin narrow, bilobate; posterior margin straight. Trulleum sub-rectangular, sclerotised, anterior corners rounded. Intermediate plate sclerotised, generally ovoid, anterior margin rounded, posterior margin connected to basal rim by membrane.

Female. ( Fig. 2B ) Head: Antennae 7 mm, 44 flagellomeres, extending to basal area of costa, yellow, weakly bipectinate, filiform appearance, poorly ciliated with few narrow and long setae. Eyes proportionally similar to male, scales on frons and vertex dense and light brown to grey. Palps longer than half length of head, three segmented, forward-projecting. Second palpomere longest, with distally club-shaped third palpomere longer than first.

Thorax: pro- and mesothorax covered in light brown-grey densely layered scales, darker on ventral surface. Legs light brown, densely scaled, epiphysis moderately long, triangular. Hind legs lighter as in male. Wings: FW: 39 mm, expanse 81 mm, elongate, narrowly triangular. Costa slightly concave centrally, convex towards apex. Apex rounded. Wing venation oxycanine. HW: 30 mm, elongate, of a similar shape as forewing but shorter, with narrower termen. Dorsal FW ground colour light brown or grey, sparsely scaled giving a generally semi-translucent appearance but not in basal area or along costa. Scales light brown-grey on wing veins, straw coloured short scales on surface. Small, angled cream spot across posterior end of discal cell usually present. Outer margin with fringe of longer scales brown, becoming light buff towards basal area of tornus. Ventral surface as above with greater extent of piliform scales on basal and costal areas. HW dorsal surface light brown to grey, unmarked. Basal area finely covered with long piliform type straw-coloured scales. Ventral surface as above, with greater extent of piliform scales.

Abdomen: broad, exceeding wing margin in habitus, first 3–4 tergites dorsally covered with straw coloured scales on all surfaces, light brown on posterior tergites.

Genitalia ( Figs 9A, B ; dis. no 31-019830-EPB; EPB-ANIC-2). Dorsal plate broad, subtriangular, with two dorso-lateral digitiform posterior projections, setose; lateral lobe of antevaginal lamella reduced, sclerotised, subtriangular and setose; subanal sclerite prominent, sclerotised, broadly triangular and projecting dorsally between ‘fingers’ of dorsal plate; medial lobe of antevaginal lamella broadly rectangular, highly sclerotised, setose. Bursa copulatrix not located during dissection, presumed damaged by egg mass.

Habitat. Oxycanus petalous sp. nov. has been taken from high-rainfall Eucalyptus tall forest environments, and from a Eucalyptus globulus plantation at Mt Barker, WA.

Remarks. Oxycanus petalous sp. nov. along with the Western Australian endemic species O. determinata , O. kochi and O. glauteri share specialized similarities in the male genitalia such as elongate, broad para-anal sclerites, and a long pseudotegumen fused at the ventral pseudoteguminal arms with species-diagnostic spines present on the pseudotegumen at varying locations. All four species also share very long, forward-facing labial palpi with the third palpomere longer than the basal palpomere. The antennae show some differences, with broader and longer rami in O. determinata ( Fig. 3E, F ) compared with those of O. petalous sp. nov. ( Fig. 3 G–H), which also has fewer but longer cilia. Generally, O. petalous sp. nov. is more plainly marked when compared with O. determinata but all four species in this group present a wing pattern and colour variations that are typical for Oxycanus species. Examination of the male genitalia has proved to be the only reliable method of separating these species. The species in this group may be allopatric, as O. kochi is known only from Drummond Cove approx. 480 km NW of the nearest O. petalous sp. nov. from Gleneagles Rest Area, while O. determinata is known by historic specimens from Perth and the Swan River district, and by more recent material collected by MDM from Esperance, ( Fig. 2C, D ). These distributions suggest that O. determinata is confined to coastal habitats, while O. petalous sp. nov. is from forested environments further inland. The exact geographic provenance of O. glauteri is unknown other than ‘Western Australia’. This situation along with the few records of O. kochi and of O. determinata indicates a need for further collecting in Western Australia to gain a more precise understanding of the biogeography of this species-group.

Figures

FIGURE 2 (A–D). Adult Oxycanus species: A, Oxycanus petalous sp. nov. holotype male; B, O. petalous sp. nov. paratype female; C, O. determinata male; D O. determinata female, ©SAMA.

FIGURE 3 (A–L) Antennae of male Oxycanus spp. A, B, O. byrsa; C, D, O. flavoplumosus sp. nov; E, F, O. determinata; G, H, O. petalous sp. nov.; I, J, O. subvaria; K, L, O. ephemerous sp. nov. Abbreviations: br—bar. ra—primary rami. ri—ridge. Scale bar in A–C is 500 µm; D is 200 µm; E, F is 500µm; G is 150µm H, I is 250 µm; J is 250 µm; K is 500 µm; L is 250 µm.

FIGURE 6 (A–F) Oxycanus spp. male genitalia. A–C, O. petalous sp. nov. dissection ID EPB-ANIC-1; D–F, O. determinata dissection ID 31-018441-EPB, ©SAMA.

FIGURE 7 (A–F) Oxycanus spp. male genitalia, 3-quarter view. A, O. ephemerous sp. nov. dissection ID 31-019191-EPB; B, O. subvaria dissection ID 31-019120-EPB; C, O. determinata dissection ID 31-018441-EPB; D, O. flavoplumosus sp. nov. dissection ID 31-018762-EPB; E, O. byrsa dissection ID 31-018407-EPB; F, O. petalous sp. nov. dissection ID EPB-ANIC-1, ©SAMA.

FIGURE 9 (A–D) Oxycanus spp. female genitalia. A & B, O. petalous sp. nov. female genitalia dissection ID EPB-ANIC-2; C & D O. determinata female genitalia dissection ID 31-019873-EPB. Abbreviations not already used: dp—dorsal plate. la—lateral lobe of antevaginal lamella. ml—medial lobe of antevaginal lamella. pp—posterior process of dorsal plate. sas—subanal plate, ©SAMA.

FIGURE 10 (A–C) Oxycanus spp. male wing venation, forewing and hindwing. A, Oxycanus ephemerous sp. nov.; B, Oxycanus flavoplumosus sp. nov.; C, Oxycanus petalous sp. nov.

FIGURE 11. Distribution records of three new Oxycanus species: grey circle—Oxycanus petalous sp. nov.; filled circle—Oxycanus ephemerous sp. nov.; empty circle—Oxycanus flavoplumosus sp. nov.

FIGURE 15. Gleneagles Rest Area, Western Australia. Sclerophyll forest habitat of Oxycanus petalous sp. n., ©P. Kay.