Metura elongatus ( Saunders, 1847 )

Beaver, Ethan P., 2020, Revision of the genus Metura (Lepidoptera: Psychidae) with description of two new species, Zootaxa 4861 (2), pp. 188-210 : 191-193

Metura elongatus ( Saunders, 1847)

( Figs 1 A–B, 3A–B, 4A–B, 4K, 5A–F, 6B, 7A, 7D, 7G, 8A–B)

= Oiketicus elongatus Saunders, 1847 : pp. 43. Nielsen et al. 1996: pp. 35.

Syntype: ♂, ‘ Oiketicus elongatus Saund. Sidney [sic] New South Wales’ in NHM. (Examined by photograph) .

Type locality: Sydney, New South Wales, Australia.

= Oiketicus saundersii, Westwood 1854 : pp. 223. Unnecessary objective replacement name. Dalla Torre & Strand, 1929, [misspelled as O. saundersi ]; Nielsen et al. 1996: pp. 35

= Phragmatoecia capucina Wallengren, 1861 : pp. 364. Nielsen et al. 1996: pp. 35.

Holotype: ♂, ‘Sidney, Novae Hollandiae, Octobris’ in NHM. (Examined by photograph).

Type locality: Sydney, New South Wales, Australia.

Additional material examined: 64 specimens (adults: 36 ♂, 1 ♀; larval bags: 26, larvae: 1) 11 ♂, 1 larva and 5 larval bags (in SAMA) : 1 ♂ North Melbourne , 10 Oct 1918, Shannon / SAMA no. 31-017586. 1 ♂ ( Fig. 1 A–B) Gippsland, Vic / SAMA no. 31-017587. 1 ♂ Warra , Qld, Lower coll / SAMA no. 31-017588. 3 ♂ ‘ Australia’ Lucas coll / SAMA no. 31-017589 to 31-017591. 2 ♂ no data / SAMA no. 31-017592 and a further specimen with 31- 017596 / Dissection ID. EPB-018. 3 ♂ Melbourne , Vic / SAMA no. 31-017593 to 31-017595. 5 larval bags: 1 ♂, 1 ♀ ‘ Australia’ Lucas coll / SAMA no. 31-017601 to 31-017602. 3 ♀ no data / SAMA no. 31-017598 to 31-017600. One larva no data / SAMA no. 31-017597. 14 ♂ and 1 larval bag (in AM) : 1 ♂ Narrabeen , NSW, 27 January 1963, P. Colman, bred . 4 ♂ Sydney , NSW . 1 ♂, Murrurundi , NSW, 10 October 1942, a further ♂ with the date 18 October 1937. 1 ♂ Woolloomooloo , NSW, 30 September 1929 . 1 ♂ North Sydney , NSW, 25 January 1915, A.S. Lindsay . 1 ♂ Manly , NSW, 10 September 1930, M. Gedale, a further ♂ with the date 15 November 1915. 1 ♂ North Ryde , NSW, 16 November 1982, C.E. Chadwick, a further ♂ with larval bag with date 10 September 1979. 1 ♂ Lower Beechmont , Qld, 1-4 January 1982, J & A. Holloway / Aus Mus no. K570249 / Dissection no. EPB-019 . 3 ♂ (in DAF) : 2 ♂ Atherton , Qld, bred 11 March 1974, 12 Feb 1974, J.H. Barrett . 1 ♂ Emerald , Qld, 11 July 1976, G. A. Waite, to light trap . 4 ♂ (in ANIC) : 1 ♂ Armidale , NSW, 26 Nov 1969, C.W. Frazier, bred ex pupa / 10ANIC-04436 . 1 ♂ Wollongong , NSW, Aust., 15 Oct 1971, V .J. Robinson / 10ANIC-04437. 1 ♂ V .J Robinson / 10ANIC-04438. 1 ♂ Ryde , NSW, 07 Oct 2004, H.S. Thirkell . 3 ♂ (in MV) : 3 ♂ no data. 1 ♂, 1 ♀, 20 larval bags (in EPBC) : 1 ♂ 19 Dec 2019, Warrumbungles , NSW, Australia, 31°15’42.5”S 148°55’27.2”E, E.P. Beaver / coll. as first instar larva 27 Dec 2018, pupated 28 May 2019, eclosed 19 Dec 2019, ex. Eucalyptus / Dissection ID EPB-017 . 1 ♀ 26 Nov 2018, Airlie Beach , Qld, Aust., 20°16’49.0”S 148°44’35.2”E, S & A. Pearson / Reared by E.P. Beaver / Dissection no. EPB-016. 20 larval bags : 2 ♂ 21 Nov 2018, Inverell , NSW, Aust., 29°47’19.3”S 151°08’18.6”E, on Corymbia maculata . 1 ♀, 1 ♂ 27 Nov 2018, East Ballina , NSW, Aust., 28°51’08.5”S 153°35’37.0”E, E.P & G.P. Beaver, on Eucalyptus and Glochidion ferdinandi . 8 ♂, 2 ♀ 21 Nov 2018, Narrabri , NSW, Aust., 30°19’42.8”S 149°46’39.0”E, E.P. & G.P. Beaver, on Melaleuca sp . 1 ♂ 11 Dec 2018, Gloucester , NSW, Aust., 32°00’14.4”S 151°57’32.7”E, E.P. & G.P. Beaver, on Melaleuca sp . 1 ♂ 08 Dec 2018, Ebor , NSW, Aust., 30°24’14.7”S 152°20’50.6”E, E.P. & G.P. Beaver, on Eucalyptus pauciflora . 1 ♂ 22 Nov 2018, Cangai , NSW, Aust., 29°33’47.2”S 152°29’14.5”E, E.P. & G.P. Beaver, on Leptospermum . 1 ♂, 1 ♀ 26 Nov 2018, Airlie Beach , Qld, Aust., 20°16’49.0”S 148°44’35.2”E, S & A. Pearson . 1 ♂ 32 km NE of Kyogle, NSW, Aust. , 28°30’01.8”S 153°11’42.3”E, E.P & G.P. Beaver, on Syzygium sp .

Diagnosis. The males of Metura elongatus are quickly distinguished from most of the other species by the colour pattern of the thorax. In M. elongatus , the patagium, tegula, and the anterior half of the mesoscutum is orange or yellow, and only the posterior half and mesoscutellum are black, whereas in the sympatric M. aristocosma , M. phyllosacca , and allopatric M. oceanica the mesoscutum is entirely black. The allopatric Metura falcata has an ‘elongatus-type’ thorax colour pattern, however may be distinguished by the shape of the hindwing, the termen of which is convex in M. elongatus and concave in M. falcata , with a more pointed apex in that species. Metura elongatus is further distinguished from M. falcata by the colour of the scales on the frons, which in M. elongatus are uniform dark brown but are light orange-yellow in M. falcata . The dark brown frons colour is shared with M. phyllosacca however in that species the frons is typically a mixture of brown and orange scales. The male genitalia are similar only to M. falcata and differences are discussed under that species. The late stage larva may be distinguished from other Metura larvae (where known) by the colouration and pattern of the head and prothoracic shield. The frontoclypeus of the head is largely orange with darker blood-orange irregular markings ( Fig 7D, G ) while in M. aristocosma the head is cream coloured, and in M. oceanica the orange colouration is broken into three sub-triangular markings, separated by black. In M. elongatus the markings of the prothoracic shield consist of four black dorso-anterior lines from the posterior edge of the shield to near but not meeting with the anterior edge, with a single white dorso-anterior line along the medial line of the shield, with the remainder orange. This contrasts with M. aristocosma , which has a mostly cream-coloured shield with yellow highlights towards the posterior edge, and black lines that extend only marginally beyond the spiracle, less than ½ the length of the shield. Additionally, the larva of M. oceanica has both the anterior and posterior edges of the shield black. The larval bag design is also diagnostic. The primary materials used in the construction of the mature larval bag are sections of sticks and twigs, with bare patches of silk visible, whereas both M. oceanica and M. phyllosacca use foliage, and M. aristocosma utilises fragments of stems and leaf veins, with no bare silk visible. The only other species to include sticks within bag design is M. falcata however this species opts for fewer, smaller twigs with wider, less regular patches of silk, and the lower ¼ of the bag is bare or poorly adorned.

Redescription. Male. ( Fig. 1 A–B, 3A–B, 8A–B) Forewing length 19–21 mm, hindwing 10–12 mm, expanse 42–44 mm.

Head. Scape trapezoidal, widest towards pedicel. Pedicel round, ½ length of scape, scape and pedicel covered in yellow-ochreous piliform scales. Antennae bipectinate, apical flagellomere filiform, 38 flagellomeres, brown scales dorsally, setose, rami 4x width of flagellomere at widest point. Frons dark brown, mixed ochreous-brown in some specimens. Vertex yellow-ochreous. Labial palps greatly reduced, two segmented, rectangular, narrow, final longest, apex pointed.

Thorax. Dorsal patagium, tegula, anterior half of mesoscutum yellow-ochreous, posterior half black, mesoscutellum black. Ventral similar. Forelegs yellow-ochreous, tarsi and posterior tibia black, mid and hindlegs black. When cleared all lightly sclerotised ( Fig. 5F ), all tibiae with rounded node at ventral anterior apex. Foreleg with narrow elongate epiphysis, femur ventrally evenly convex. Mid and hindleg with two reduced, rounded tibial apical spurs. Forewing elongate, triangular; costa slightly concave medially, gently convex toward blunt apex, termen convex medially, inner margin concave posteriorly, convex anteriorly. Hindwing costa highly convex, apex blunt, termen convex, inner margin greatly expanded, convex, angular where A1 meets margin. Both forewing and hindwing surface black, all veins weakly scaled, translucent. Underside as for above.

Abdomen. Dorsally black, interspersed with yellow-ochreous scales at posterior 1/3 rd and weakly between tergites. Ventral similar, yellow-ochreous from posterior ½. Sternite SVIII ( Fig. 4K ) narrow, elongate, paired anterior apophyses wide-set, apexes pointed, posterior-lateral corners rounded.

Genitalia. ( Fig. 4 A–B). Saccus narrow, elongate, posterior margin broad ‘U’ shaped. Vinculum with vincular arms straight, parallel on inner margin with saccus, outer margin at acute angle towards tegumen, more heavily sclerotised towards tegumen. Tegumen outer margin slightly concave. Uncus broad, wider than high, posterior apex rounded, bifurcate, setose on dorsal aspect. Transitellar arms sclerotised, anterior margin convex, posterior straight. Valvae elongate, apexes bifurcate to two subequal-sized lobes, ventral lobe hooked, short spines at apex, inner dorsal margin setose with short irregular spines, sacculus heavily spined, globular, rugose texture. Phallus elongate, ventrally concave, dorsally convex, ductus ejaculatorius heavily spined, vesica smooth, pronounced uneven mushroom-shape, dorsal aspect almost twice length of ventral.

Female. ( Figs 5 A–C, E) 50 mm length. Larviform entire body transparent. Head reduced, eyes present. Thorax dorsally sclerotised ( Fig. 5E ), light brown, legs simple with single tarsal claw. Abdomen weakly sclerotised, yellow in life, corethrogyne broad, consisting of downy golden scales present in a ring around the sixth and seventh abdominal sternites and tergites, with additional scales present on TV and SV as a weak ring.

Genitalia. ( Fig. 5D ) Apophyses anteriores reduced, arising from heavily sclerotised sternite. Apophyses anteriores moderately long.Antrum subtriangular, rugose. Corpus bursae ovoid, diverticulum narrow. Ductus bursae short, narrow. Ovipositor short, simple.

Larva. ( Fig. 7A, D, G ) Head light to dark ochreous, with irregular darker patterns present on frontoclypeus particularly around setae. Maxilla, mandible dark ochreous. Pronotal shield of thorax dark ochreous with anterior margin ochreous, posterior and lateral margin black. Two black parallel lines along lateral surface, not meeting with anterior margin. Medial line narrow, white. Meso- and metathorax similarly patterned except anterior margins and interscleral membranes black or dark grey. Thoracic legs dark reddish brown, heavily sclerotised.

Larval Bag. ( Fig. 6B , 7A ) 80–160 mm length, 10–20 mm width. Silk grey to whitish cream. Adorned primarily with sections of twigs and stems from larval food plant, attached in loose parallel rows with areas of bare silk between each adornment. Twigs utilised may vary between 4–60 mm long, longest twigs attached near to posterior apex, attached along first ¾ length with remaining section free. Posterior apex often heavily adorned with narrow twigs, leaves or floral foliage.

Distribution. Metura elongatus is widespread in the higher rainfall regions of eastern Australia ( Fig. 9B ), from the Atherton Tableland in northern Queensland, south to Flinders Island, Tasmania, and as far west as Mount Gambier, South Australia ( ALA, 2020). In north Queensland the known records are mainly coastal or coastal montane, where rainfall is more reliable than further inland.

Biology and phenology. This species is highly polyphagous, and the larvae have been recorded feeding on a wide variety of plants, both angiosperms and gymnosperms, particularly Melaleuca , Leptospermum , Eucalyptus (Myrtaceae) , Citrus (Rutaceae) , Cotoneaster (Rosaceae) , Cupressus (Cupressaceae) , Pinus (Pinaceae) , ( Common 1990) while additionally the present author has reared larvae on Corymbia , Psidium , Syzygium (Myrtaceae) , Banksia , Grevillea (Proteaceae) , Alyogyne (K. Messenger pers. comm.) Hibiscus (Malvaceae) , Ligustrum (Oleaceae) , Glochidion (Phyllanthaceae) , Rosa (Rosaceae) , Cyrtostachys (Arecaceae) , Pelargonium (Geraniaceae) , Alphitonia (Rhamnaceae) , Casuarina , Allocasuarina (Casuarinaceae) Lomandra , ( Asparagaceae ), and Dietes (M. Connors pers. comm) ( Iridaceae ). Young larvae construct a larval bag from fragments of leaves during their first four larval instars before transitioning to the utilisation of sections of twigs. A larva halfway through this transition is depicted in Figure 7A . New twigs are added irregularly near the anterior aperture via a temporary incision in the bag (figured in: Clyne 2009). There is some sexual dimorphism in bag structure particularly length and width, with some female larval bags up to 160 mm long, and most males between 100–120 mm. Larger female specimens often opt to utilise many, smaller twigs rather than many larger ones. Several specimens are known with a single, very long twig or blade-like leaf, often these are male specimens however this feature is unreliable as considerable variation and overlap is known. Freshly moulted larvae are white, gradually darkening to orange over a series of days. There may be some clinal variation in the mature larvae of this species, with specimens from the northern part of the range a deeper orange, with a more prominent white medial line on the prothoracic shield. Larval development (first instar to pupation) is approximately 5–6 months (n= 4 larvae) while pupal duration for a single male specimen was 6 months and 21 days. Larval stages may be parasitised by wasps of the family Ichneumonidae Latreille ( Saunders 1847) , particularly Echthromorpha intricatoria ( Fabricius, 1804) and flies of the family Tachinidae Robineau-Desvoidy , such as Chlorogastropsis orga ( Walker, 1849) (L. Kirchmajer pers. comm). The adult male Metura elongatus are nocturnally active and are attracted to UV and MV light generally between September and March. Unlike the larvae, which may be locally abundant and commonly encountered, adult specimens are rarely collected and are generally poorly represented in museum collections. Metura elongatus will occur in a wide range of woodland ( Fig. 10B, C ) and forest environments including temperate, subtropical, and tropical rainforest ( Fig. 10A, D ), subalpine woodlands, agricultural and semi-urban environments such as parks, gardens, street trees.

Remarks. Both the type specimen of Oiketicus elongatus and Phragmatoecia capucina are extremely worn, poorly set, and are of only minimal use comparatively. For this reason, an intact specimen typical of this species is figured instead of a type, to allow for easy comparison between this and the following Metura spp.

Figures

FIGURE 1. Adult male Metura spp., dorsal and ventral. A–B, M. elongatus (Sydney, NSW, AU), C–D, M. falcata sp. n. holotype (Lorde Howe Isl, AU). Scale bars: 10 mm.

FIGURE 4. Male genitalia of Metura: A–B, M. elongatus dissection ID EPB-017, C–D, M. falcata sp. n. dissection ID EPB- 020, E–F M. oceanica from Viette (1963) with modification, G–H, M. aristocosma dissection ID EPB-021, I–J M. phyllosacca sp. n.; I, dissection ID EPB-022, J, dissection ID EPB-024. K–N: sternite eight, K, M. elongatus dissection ID EPB-017, L, M. oceanica from Viette (1963) with modification, M, M. aristocosma dissection ID EPB-021, N, M. phyllosacca sp. n. dissection ID EPB-024. Abbreviations: aa—anterior apophysis. de—ductus ejaculatorius. sa—saccus. sc—sacculus. tg—tegumen. trtransitellar arm. un—uncus. va—valvae. ve—vesica. vi—vinculum. Scale bars: 1 mm.

FIGURE 5. Details of adult Metura morphology. A–E, female Metura elongatus (Airlie Beach, Qld, AU), A, dorsal, B, ventral, C, lateral, D, genitalia dissection ID EPB-016, E, close-up of head and thorax (cleared). F–I, legs of male Metura spp., F, M. elongatus dissection ID EPB-017, G, M. falcata sp. n. holotype dissection ID EPB-020, H, M. aristocosma dissection ID EPB-021, I, M. phyllosacca sp. n. paratype dissection ID EPB-022. J, wing venation diagram of M. phyllosacca sp. n. paratype (Noosa, Qld, AU). Abbreviations:A—anal vein. am—antrum. an—apophyses anteriores. ap—apophyses posteriors. cb—corpus bursae. CuA—anterior cubital vein. CuP—posterior cubital vein. Fr—frenulum. H—humeral vein. M—medial vein. op—ovipositor. R—radius. Rs—radial sector vein. Sc—subcosta. sVIII—eighth sternite. Scale bar for A = 5 mm, D = 1 mm, E–I = 2 mm.

FIGURE 6. Larval bags of male Metura spp., A, M. aristocosma, B, M. elongatus (Narara, NSW, AU), C, M. phyllosacca sp. n. (Banyabba, NSW, AU), D, M. falcata sp. n. (Neds Beach, Lord Howe Isl, AU), E, M. oceanica (Duck Isl, NC). Abbreviations: aa—anterior aperture. fa—foliage adornment. pa—posterior aperture. Scale bar: 20 mm.

FIGURE 7. Larvae of Metura spp., A, M. elongatus (Warrumbungles, NSW, AU) approximately fifth instar with intermediate bag structure, B, M. oceanica (Pouembout, NC) active early instar larval bag on Ixora margaretae, C, M. aristocosma (Kuranda, Qld,AU) late instar larva, D, M. elongatus (Brisbane, Qld,AU) close-up of head and pronotal shield, E, M. oceanica (Mt Katépaï, Voh, NC) recently eclosed male larval bag with empty pupal exuvia at anterior aperture, F, M. oceanica (near Paagoumène, NC) late instar larva, G, M. elongatus (Vic, AU) late instar larva close-up of head and thorax, H, M. aristocosma (Julatten, Qld, AU) active mature larval bag. Figure B, E courtesy of J. Barrault, C courtesy of A. Mitchell, D courtesy of J. Thynne, F courtesy of E. Bourguet, G courtesy of V. Dunis, H courtesy of D. Herrington.

FIGURE 9. Distribution of Metura spp., A, M. phyllosacca sp. n. blue circle, M. falcata sp. n. red circle, M. oceanica yellow circle, M. aristocosma green circle, Metura spp. (undescribed) grey circle; B, M. elongatus purple circle.

FIGURE 10. Habitats of Metura spp., A, subtropical rainforest at Mt Glorious, Qld (M. phyllosacca sp. n. and M. elongatus, B, Open Eucalyptus woodland and diverse heath at Gibraltar Range NP, NSW (M. elongatus), C, subtropical Eucalyptus, Casuarina and Alphitonia early succession woodland at Banyabba, NSW (M. phyllosacca sp. n. and M. elongatus), D, upland tropical rainforest at Kuranda, Qld, (M. aristocosma, M. elongatus, M. phyllosacca sp. n.). D courtesy of A. Henderson.