Aenetus albadamanteum Beaver & Grehan, 2020

Beaver, Ethan P., Moore, Michael D., Grehan, John R., Velasco-Castrillón, Alejandro & Stevens, Mark I., 2020, Four new species of Splendid Ghost Moths (Lepidoptera: Hepialidae:) from Australia and Papua New Guinea, Zootaxa 4809 (3), pp. 449-474 : 461-469

Aenetus albadamanteum Beaver & Grehan , sp. nov.

( Figs 44–45 , 46–49, 51–54 )

Type specimens: Holotype ♂, ANIC . Paratypes: 1 ♀ ANIC , 1 ♀ BPBM , 1 ♂ CNC .

Type locality: Mount Kaindi, Morobe Province, Papua New Guinea.

Etymology. The name albadamanteum is from the Latin alba, ‘white’, and adamantem ‘diamond’, referring to the white, diamond shaped markings present along the medial and sub-marginal lines of the forewing, particularly in the female. A noun in the nominative singular case.

Type material. HOLOTYPE (in ANIC) ♂. [Papua] New Guinea: NE: [Morobe Province] Mount Kaindi, 2350 m, February 1970, J.H. Sedlacek, Rainforest / Dissection no: EPB-ANIC-019 / ANIC 31-071242 .

PARATYPES. 1♀ (in ANIC) Same data as holotype except date as 01 January 1979 / Dissection no: EPB- ANIC-020 / ANIC 31-071243 . 1 ♀ and 1 ♂ in BPBM : ♀ Mt. Kaindi, NG, 2350 m, 23.III.1966 / Light trap, J.L. Gressitt / Dissection no: JRG 300. 1 ♂ PNG, Bulldog Road , 7 km s Edie Creek, 2400m, 13-15-xii 1977, UV lt, P. Herbert & R . Harmsen / Dissection no: JRG208 .

Distribution. Known only from Mount Kaindi, Morobe Province, Papua New Guinea ( Fig. 58 ).

Diagnosis. This species is not easily mistaken for any other species that occur in Papua New Guinea. It is superficially similar to A. crameri , A. hampsoni and A. toxopeusi , but without the prominent ‘X’ shaped markings present between most veins on the forewing of those three species. Furthermore, A. albadamanteum sp. nov. is the only one of the four species to have two rows of black spots along the medial and submarginal lines in the male. A female of A. hampsoni figured in Joicey & Noakes (1914) differs from A. albadamanteum sp. nov. by the presence of numerous bright white ‘X’ shaped markings present in a medial and submarginal line as well as along the wing margin and basal area. Although females of A. crameri and A. toxopeusi are currently unknown, Viette (1956) figured the male genitalia of both species and these differ from that of A. albadamanteum sp. nov., particularly in the valvae where the apex is bulbous, and by the anterior end of the apodemal vinculum, which has only short, close-set anterior projections, which are much larger and wider-set in A. crameri and absent in A. toxopeusi . Aenetus bilineatus is the only other New Guinean species which has a well-defined medial and sub-marginal band in the forewing, however in A. albadamanteum sp. nov. the bands are comprised of a series of disconnected spots, whereas in the former species the spots are merged as a continuous line, and the hindwing is very broad and more rounded compared with the narrow hindwing of A. albadamanteum sp. nov.. Aenetus bilineatus is also smaller, with a male forewing length of 36 mm. Aenetus albadamanteum sp. nov. is similar to the New Caledonian A. cohici . Grehan (1983) described and figured the male genitalia of A. cohici ( Fig. 50 ), a species that differs significantly from A. albadamanteum sp. nov. in the shape of the valvae, which lack the bulbous apex, and the apical teeth proportionally longer. Male wing pattern in A. cohici is highly variable ( Salesne 2010) but includes variations where males have a medial and submarginal line of disconnected spots. Unlike A. albadamanteum sp. nov., which has dark brown spots, the spots of A. cohici are primarily white with a narrow edge of brown on the outer edge. The new species lacks the knob-shaped metatibial scent gland found in A. cohici ( Grehan 1983, Fig. 1 )

Description. Male ( Fig. 44 ). Forewing: 46 mm. Hindwing: 40 mm. Expanse: 83 mm. Head: antennae longer than head and fine, filiform, pale brown, at least 23 flagellomeres, scape cuboid, pedicel ovoid. Eyes prominent, wide-set, slightly higher than head capsule. Scales on frons and vertex dense and light green. Labial palps with three palpomeres, basal two rectangular, third rounded; basal palpomere longest, distal-most shortest.

Thorax: Pro and mesothorax dorsally and ventrally covered in light green scales and interspersed with orange and yellow scales on ventral surface. Legs uniformly green and light brown, foreleg missing, hind tibia thickened, with large ochreous metatibial tuft of very long androconial scales characteristic of Aenetus . Arolium u-shaped.

Wings: Forewing broad and triangular. Costa centrally straight and convex towards apex. Apex pointed, wing venation classically hepialine. Hindwing of similar width to forewing, sub-triangular with sharp acute angle at apex. Dorsal forewing ground colour light green with alternating dark green lines between all wing veins, and two transverse rows of dark grey spots, one spot between each wing vein; a series of nine semi-circular spots along medial line between inner margin at 1A and costa, spots between Rs3 and CuA2 with silver centre, and submarginal series of diamond-shaped dark grey spots between Rs2 and CuA2; Rs3 to M2 with silver centre. Six to seven light brown bars separated by green along costa with darkest bar medially. Wing margin with three brown spots between each wing vein, between Rs1 and CuA1, largest spot centrally. Ventral surface plain, spots visible faintly through wing, faint yellow scales centrally and basally. Hindwing dorsal surface bright white, tornus and inner margin pale greenish-cream at margin, fading into white ground area. Sc and Rs1 straight. Apex acutely pointed. Basal area covered with white piliform scales.

Abdomen: elongate, narrow, scales white. Sternite eight ( Fig. 54 ) subsquare, narrowing slightly posteriorly, anterior margin tapering to shallow point, posterior margin indented slightly each side of a shallow medial convex protrusion.

Genitalia ( Figs 46–48 ): Apodemal vinculum broad and short, with paired anterior projections rounded, closeset. Saccus triangular, broad. Intermediate plate laterally compressed, sub-trapezoidal, free. Basal rim of pseudotegumen broad, high in lateral view, disto- and ventroposterior margins of pseudotegumen broad, sub-triangular. Ventral pseudoteguminal arm membranous. Valva ( Fig. 49 ) short, broad at proximal end, with short, square sacculus. Viewed posteroventrally, valvae curve laterally away from pseudotegumen. Apex of valva bulbous, with very short apical spine. When viewed laterally in situ this apical spine is positioned almost horizontally. A large curving hook from middle of valva points vertically ventrally. A second hook positioned just above the sacculus, less curved and longer than middle hook. Fine setae present ventrally between sacculus and valva apex. Juxta flattened and Ushaped. Truellum membranous.

Variation. Paratype male has the diamond-shaped grey spots of the forewing with a more prominent white centre. Width of valval hooks and juxta variable, level of sclerotisation of pseudotegumen may differ between specimens.

Female ( Fig. 45 ). Forewing: 86 mm. Hindwing: 57 mm. Expanse: 157 mm. Head: antennae longer than head and fine, filiform, pale brown, 34 flagellomeres, scape rectangular, pedicel ovoid. Eyes prominent, widely spaced, slightly higher than head capsule. Scales on frons and vertex dense and light green. Palps as for male, basal two partially fused.

Thorax: Pro- and mesothorax dorsally and ventrally covered in light green scales interspersed with orange and yellow scales on ventral surface. Legs uniformly green and light brown with epiphysis digitiform; arolium as for male.

Wings: Similar to male, hindwing proportionally shorter, forewing broad and triangular. Costa straight centrally and convex towards pointed apex. Wing venation as for male except 2A present in hindwing. Hindwing narrower, sub-triangular with sharp angle at apex and tornus. Dorsal forewing ground colour as for male, spots larger and all with white centre, all diamond-shaped except for semi-circular spots on medial line between Rs4 and M2. Two irregularly shaped grey spots with white centre in discal cell nearest to costa; central and posterior discal cells each with a single irregularly shaped white-centred spot; a further single white-centred spot at distal end of CuP, faint grey spot at middle of CuP. At least three light brown bars separated by green along costa, with darkest bar medial (costa worn of scales). Outer margin with single brown spot between each wing vein from Rs1 to CuA1. Ventral surface plain, spots visible faintly through wing, faint yellow scales centrally and basally. Hindwing dorsal surface pale greenish-yellow, faint pink basally. Green scales irregularly scattered in sub-marginal area to margin. Apex acutely pointed. Faint pink-cream piliform scales basally.

Abdomen: elongate, narrow, scales green, pinkish basally.

Genitalia ( Figs 51–53 ): Dorsal plates wide, lightly sclerotised, setose, posterior-medial ends narrow, fused across the median. Subanal plates narrow, dorsal edge with irregular indentations. Antevaginal lamella dorso-ventrally high, setose, well sclerotized, particularly along dorsal edge. Dorsal edge medially truncate, lateral lobes dentate along dorsal margin. No clear distinction between medial and lateral areas. Ductus bursae long and narrow, diverticulum short, about 1/3 length of corpus bursae, cylindrical, apically tapered to round end, connected to a broadened section of corpus bursae. Corpus bursae elongate, broad, angled slightly before becoming distally wider and sub-ovoid.

Variation. No significant variation observed.

Biology and phenology. Larval biology unknown. The holotype and two paratype specimens were taken near the summit of Mt Kaindi (alt. 2362 m), at the recorded elevation of 2350 m Mt Kaindi is predominately lower montane rainforest dominated by Nothofagus pullei Steenis (Nothofagaceae) , with other tree species such as Acronychia J.R.Forst. & G.Forst. (Rutaceae) , Elaeocarpus polydactylus Schltr , Sericolea micans Schltr. (Elaeocarpaceae) , Homalanthus nervosus J.J.Sm. (Euphorbiaceae) , and Quintinia macrophylla Hatschb. (Paracryphiaceae) . In the 1990’s this vegetation was reportedly in early-mid succession, having been disturbed by mining and related activities such as continued clearing and burning ( van Valkenburg & Ketner 1994) especially the lower slopes. This activity has continued and the environment present is now highly degraded including the summit (N. Grimaldi pers. obs; Fig. 66 ). The response of this species to this level of disturbance is unknown. A further specimen collected from south of Edie Creek, which is approximately 10 km SW of Mt Kaindi, was taken at a similar altitude of 2400 m. All known specimens are from the 13th of December to the 23 rd of March, which may indicate a fairly long flight time.

Remarks. The holotype and one paratype have some historic damage by the pest beetle Anthrenus Geoffroy ; the holotype male is less affected though there is some damage to the abdomen, tornal area of the forewings, and considerable scale loss has occurred across much of the thorax and abdomen of both specimens. Hepialidae are well known to fade after collection. In life the wing colouration, particularly in the hindwing basal area of the female, would likely be much brighter.

Figures

FIGURE 58. Distribution records of the Aenetus hampsoni species group in New Guinea; pink circle: Aenetus albadamanteum sp. nov.; dark grey circle: A. crameri; light grey circle: A. toxopeusi; black circle: A. hampsoni.

FIGURE 66. View of Mt Kaindi area, PNG. Environmental degradation via mining activity apparent in centre, while deforestation apparent broadly but particularly centre-left. Remnant montane rainforest present lower centre and on distant hill face. Figure courtesy of N. Grimaldi.

FIGURE 44–45. Aenetus albadamanteum sp. nov. (all dorsal); 44, holotype male; 45, paratype female. Scale bar: 10 mm.

FIGURE 46–54. Male and female Aenetus spp. genitalia and sternite eight. 46–48, A. albadamanteum sp. nov. holotype, dissection ID EPB-ANIC-019, male ventral, dorsal, lateral; 49, A. albadamanteum sp. nov. holotype, valva; 50, male A. cohici, New Caledonia, ventral (image J.R. Grehan); 51–53, A. albadamanteum sp. nov. paratypes; 51, bursa copulatrix JRG208; 52–53, dissection ID EPB-ANIC-020; 54, male A. albadamanteum sp. nov. holotype, sternite eight. Scale bars: 46, 54: 1 mm, 49: 500 μm, 52-53: 2 mm.

FIGURE 1–6. Adult male Aenetus spp: 1–2, A. simonseni sp. nov., holotype, 1, dorsal; 2, ventral; 3–4, A. thermistis, Atherton, QLD, 3, dorsal; 4, ventral; 5–6, A. maiasinus sp. nov., holotype, 5, dorsal, 6, ventral. Scale bars: 10 mm.