Synemon cacumina Kallies & Edwards, 2020

Kallies, Axel, Edwards, Edward D. & Williams, Andrew A. E., 2020, New and little-known sun-moth species from Australia (Lepidoptera, Castniidae), Zootaxa 4895 (2), pp. 151-195 : 184-187

Synemon cacumina Kallies & Edwards sp. n.

Hilltop Sun-moth

Figs 67 , 77–80 , 81 , 92, 93

Literature: Williams et al. 2016: 108–110, figs 18, 19 (as ‘ Synemon sp. Mount Ragged’).

Material examined. Holotype: Ƌ ‘heathland above escarpment approx. 20 km WNW of Israelite Bay , W.A. 29 Dec. 1990 M.S. & B.J. Moulds’ ( Figs 77, 78 ) ( ANIC) . Paratypes: 7 Ƌ, labelled as holotype ( ANIC, AMS) ; 2Ƌ, 3 km SW Mt Ragged, Cape Arid N.P., 18.xii.1989, R.P. Fields ( ANIC) ; 6Ƌ, heathland above escarpment approx. 20 km WNW Israelite Bay , 29.xii.1990, M.S. & B.J. Moulds ( Fig. 81 , genitalia and leg slides 11853, 11854, 13064) ( ANIC, AMS) ; 2♀, 26 km E Ravensthorpe , 33.36S 120.18E, 6.i.1993, E.D. Edwards, E.S. Nielsen ( Figs 79, 80 ) ( ANIC) ; 1Ƌ, Mt Ragged , 10.xii.1974, K.T. Richards ( WAM) ; 8Ƌ, Cape Arid N.P., The Diamonds Hill , 3338’46” S 12329 ’13”E, 4.i.2017, A.A.E. Williams ( WAM) ; 2Ƌ, Fitzgerald River N.P., East Mount Barren , 3412’59.5” S 11925 ’58.9”E, 11.i.2015, A.A.E. Williams ( WAM) ; 2Ƌ, Stirling Ranges, Lookout Hill alongside Red Gum Pass , 16.xii.2004, A.A.E. Williams ( ANIC, CAK) ; 1Ƌ, Stirling Ranges N.P., 12 km E Mondurup Peak , 28.i.1994, A.A.E. Williams ( ANIC) ; 1♀ Stirling Ranges , 13.i.1974, K. & E. Carnaby ( Fig. 67 , genitalia slide 13063) ( ANIC) ; 7Ƌ, Stirling Range N.P., 3425.508’S 11756.101’E, 18.xii.2004, 19.xii.2004, 20.xii.2004, 21.xii.2004, 22.xii.2004, 23.xii.2004, 24.xii.2004, A.A.E. Williams ( WAM) ; 7Ƌ, Stirling Range N.P., 3425.508’S 11756.104’E, 29.xii.2009, A.A.E. Williams ( WAM) .

Etymology. The species’ name is derived from the Latin cacumen (summit, mountain top) and relates to the preference of this species to hilltop.

Description. Male ( Figs 77, 78 ). Alar expanse 40–42 mm, forewing length 19–21 mm, body length 18–20 mm. Head, vertex with black piliform and lamellar scales, frons with pale brownish grey scales, labial palpi short, upturned, not reaching frons, appressed to head, white, haustellum well developed, antenna with long seta on each flagellar annulus, sometimes more, projecting posteriorly, black annulated with white scales, flagellar annuli white beneath, club arising abruptly, black above, white proximally beneath, nudum 11–12 brown on anterior half of club, apiculus narrow. Thorax above black, of mixed piliform and broad lamellar scales, beneath pale orange and white, legs brown to pale orange above, white beneath, epiphysis clothed in short spines, pointed at tip, reaching to about end of foretibia. Abdomen black above, T2–T4 with numerous long grey scales, beneath pale orange.

Forewing costa almost straight, apex sharply rounded, termen rounded, inner margin slightly rounded. Upperside black with markings of white and grey scales; basal third of wing with scattered grey scales, an area of ground colour crosses disc from costa to inner margin forming a prominent black band, a white patch at end of cell large, extending to costa and towards inner margin but in posterior half of wing obscured by grey and some black scales, this band bordered distally by scattered grey scales on black ground colour, a subapical band of white or grey spots from R2 to M3, straight and forming a broad band, an ill-defined area of black with grey scales which define a band of black spots, largest near apex, beyond subapical band, a terminal line black. Cilia black. Underside black with pale orange and white markings; pale orange at base extending half way along cell, a pale orange median band from costa to near inner margin, a broad subapical band from R2 to M3 white with a pale orange border, a submarginal band of discrete white spots between the veins from costa to M3 and a terminal black line. Cilia dark grey.

Hindwing termen evenly rounded, tornus rounded. Upperside black with orange and white spots; a small orange spot at distal end of cell, a narrow median band of small orange spots extending from M1 to 1A+2A, those spots between M1 and M3 confluent, a gap of ground colour to CuA1 and a narrow orange band extending from CuA1 and 1A+2A, a submarginal band of two white spots one between M3 and CuA1 the other between CuA2 and 1A+2A, anal area grey and with an ill-defined submarginal orange band. Cilia black, white from Rs to M2 and black at tornus. Underside black with white and orange spots; basal third of wing pale orange mixed with black, a white spot at distal end of cell extending anteriorly to Sc+R1, a median band of white spots bordered distally by orange from apex to 1A+2A, spots between M1 and M3 confluent, spot absent between M3 and CuA1, a submarginal row of minute white spots from Sc+R1 to 1A+2A, those spots between M3 and CuA1 and CuA2 and 1A+2A much larger, a narrow terminal line black, anal area with some pale orange scales with a small white and pale orange tornal spot. Cilia dark grey, white anterior to M3, paler at tornus.

Female ( Figs 79, 80 ). Alar expanse 47–48 mm. Similar to male, larger, termen more rounded, wings slightly broader, coloration similar to male but orange and white bands larger. On the underside, the basal third of both wings is pale orange. On the hindwing, there is a black spot in the middle of the cell and the anal area is broadly orange, the median band is broad, orange and without interruption.

Male genitalia ( Fig. 81 ). Uncus broad, of uniform width, evenly rounded at tip with long setae; gnathos arms shorter than uncus; anal tube sclerotized; tegumen broad, curved, parallel sided; vinculum evenly, strongly, sclerotized; saccus without bifurcated arms; juxta well sclerotized, curved anteriorly; valva elongate, tip truncated into upturned point, sacculus and costa with stout setae, ventral margin almost straight; phallus short, well sclerotized, of even diameter, tip oblique, gently curved, with phallobase large and strongly recurved; ductus ejaculatorius much longer than phallus, with several coils.

Female genitalia ( Fig. 67 ). Papillae anales short pointed sclerotized; ovipositor long, narrow, extensible, sclerotized, with numerous stout dorsal and lateral spines towards tip; apophyses long, heavily sclerotized, apophyses anteriores about half the length of apophyses posteriores which extend from the tip of the papillae; sinus vaginalis with two short lateral sacs; ostium bursae at posterior edge of S7; ductus seminalis from near ostium; ductus bursae with numerous spicules and one coil; corpus bursae large, approximately spherical, membrane rugose, with two well developed paired scobinate signa.

Diagnosis. Synemon cacumina sp. n. is easily recognised by the narrow bands on the upperside of the hindwing. The median band is orange while the submarginal band consists of two white spots. The forewing above is also distinct with the white discal spot at the end of the cell greatly enlarged and extended into a band nearly crossing the wing. Females of S. maja can sometimes have a similar band but the hindwings are very different. The shape of the forewing also differs from the S. leucospila group of species which have a more rounded costa.

Variation. There is variation in size and in the width of the orange median band on the upperside of the hindwing.

Distribution. Synemon cacumina sp. n. has been recorded at Stirling Range National Park in the west, east to West Mount Barren in Fitzgerald River National Park, 26 km east of Ravensthorpe, Mount Ragged and The Diamonds Hill in Cape Arid National Park, and the area round Israelite Bay. A photographic record from the Porongurup (1Ƌ, Porongurup, Plantagenet, Twin Creek Conservation Reserve, -34.62339 117.892787, 27.xii.2017, Steve Dew, iNaturalist, Fig. 92 ) requires confirmation.

Habitat and Biology ( Fig 92, 93 ). This species has been recorded between 10 December and 28 January. The type locality is above the escarpment near Sheoaks Hill, along the road from Israelite Bay to Mount Ragged in Cape Arid National Park. It generally favours mixed mallee and heathland, and has been observed visiting flowers ( Fig. 92 ). The larval food plant is unknown. Synemon cacumina sp. n. is the only sun-moth species in Australia, currently known to exhibit classic hill-topping behaviour. Males may be located at the summits of prominent hills, where they often fly together with hill-topping butterflies. At Stirling Range National Park males hill-top at the summit of the look-out hill on Redgum Pass Road, at Fitzgerald River National Park at the summit of West Mount Barren, and at Cape Arid National Park at the summit of The Diamonds Hill (Williams et al. 2016). This species can be numerous on hilltops in the aftermath of fire. The male sun-moths fly in sunny conditions, periodically settling on prominent shrubs at the tops of the hills. Females are rarely seen. Hill-topping behaviour has been also reported for Synemon jcaria R. Felder 1874 ( Douglas 2008) . Similarly, Synemon gratiosa Westwood 1877 often occupies sandy hilltops and dune ridges (Williams et al. 2016). But with both species, their host food-plants are always present on the occupied hilltops, and the males hold territories.

Remarks. This species was listed as Synemon sp. ‘Mount Ragged’, the Hilltop Sun-moth by Williams et al. (2016).

Figures

FIGURE 81. Synemon cacumina sp. n., paratypes, male genitalia. a. Unrolled. b. Lateral view, right valva removed. c. Valva. d. Phallus (genitalia slides ANIC 11853, 11854) (ANIC).

FIGURES 64–67. Synemon species, female genitalia. Signum (left), anterior part (middle), posterior part (right). 64. Synemon semaphora sp. n., paratype (genitalia slide 13052). 65. Synemon petrophila sp. n., paratype (genitalia slide 13066) (ANIC). 66. Synemon angustiptera sp. n., paratype (genitalia slide 13046) (ANIC). 67. Synemon cacumina sp. n., paratype (genitalia slide 13063) (ANIC).

FIGURES 77–80. Synemon cacumina sp. n., upperside (left), underside (right). 77, 78. Ƌ, paratype, Israelite Bay (ANIC). 79, 80. ♀, paratype, Ravensthorpe (ANIC).

FIGURES 92–94. Synemon habitat and biology. 92, 93. Synemon cacumina sp. n., male, Porongurup (92, image James Peake), habitat at Lookout Hill, Stirling Range (93). 94. Synemon victoriae sp. n., habitat at Boondi Rock, larval food-plant Lepidosperma drummondii.