Pleioplectron auratum, Hegg & Morgan-Richards & Trewick, 2019

Hegg, Danilo, Morgan-Richards, Mary & Trewick, Steven A., 2019, Diversity and distribution of Pleioplectron Hutton cave wētā (Orthoptera: Rhaphidophoridae: Macropathinae), with the synonymy of Weta Chopard and the description of seven new species, European Journal of Taxonomy 577, pp. 1-46 : 22-24

Pleioplectron auratum sp. nov.

urn:lsid:zoobank.org:act:97429B5F-54CF-4891-8174-64F038866150

Figs 2 A–B, 6E, 7E, 8M–O, 10M–O, 15A, 18E

Diagnosis

A small to medium-sized cave wētā found in forests and in urban and disturbed habitats in the northeast corner of South Island. The habitus is typical of Pleioplectron , chequered grey-brown in colour, with visibly banded legs and with a dorsal median line ( Fig. 15A ). A prominent pair of longer spines stands out on the hind tibia, about one third of the way up from the apex ( Fig. 7E ). Relative to body size, the ovipositor is longer than in any other species of this genus. Pleioplectron auratum sp. nov. is most similar to P. triquetrum sp. nov., although it is generally lighter in colour. An examination of the terminalia is required to reliably tell the two species apart from each other.

Etymology

ʻ Aurātus ʼ is Latin for ‘adorned with gold’, because of the fine golden hair that adorns the posterior margins of the insect’s tergites.

Material examined (see also Table 6 in Supplementary Material)

Holotype

NEW ZEALAND • ♂, adult; Marlborough Sounds (SD), Rarangi, Whites Beach , Black Jack Track ; 41.384238° S, 174.058243° E; 20 m a.s.l.; 12 Dec. 2018; Danilo Hegg leg.; on clay bank on side of track in native forest; night search + insect net; NMNZ AI.037482 (prev. MPN CW4295 ).

Paratype

NEW ZEALAND • ♀, adult; Marlborough (MB), Blenheim, New Renwick Rd ; 41.526987° S, 173.8478117° E; 40 m a.s.l.; 28 Sep. 2018; Danilo Hegg leg.; in firewood pile; night search + insect net; NMNZ AI.037483 (prev. MPN CW4119 ) .

Other material

NEW ZEALAND – Marlborough (MB) • 1 nymph; Blenheim, Onamalutu Rd ; 41.47045° S, 173.73144° E; 50 m a.s.l.; 3 Apr. 2018; D. Hegg leg.; in stone retaining wall on roadside; night search + insect net; MPN CW3940 • 1 ♂, 1 ♀; same collection data as for paratype; MPN CW4105 , CW4120 • 1 ♀; same collection data as for paratype; 19 Oct. 2018; MPN CW4142 • 3 ♂♂, 3 ♀♀; Blenheim, Waihopai River ; 41.52456° S, 173.73504° E; 80 m a.s.l.; 19–22 Oct. 2018; D. Hegg leg.; in flooding debris next to river; night search + insect net; MPN CW4141 , CW4143 to CW4147 . – Marlborough Sounds (SD) • 1 ♀, 2 nymphs; Picton, Bob’s Bay Track; 41.28757° S, 174.01008° E; 10 m a.s.l.; 11 Dec 2018; D. Hegg leg.; disturbed vegetation, bank on side of track; night search + insect net; MPN CW4235 , CW4236 , CW4281 • 1 ♂; same collection data as for holotype; MPN CW4294 .

Description

MEASUREMENTS. See Table 1.

HEAD. Frons glabrous, mostly pale, with dark patches under eyes and in middle; vertex glabrous and of variegated colour. Eyes dark. Fastigium dark, with a white spot on either side. Scapes and peduncles variegated and pilose, with dark antennae covered in fine setae. Maxillari and labial palpi light brown, with fine tomentum.

THORAX. Pronotum mottled with pale and dark patches, but dark with pale bars next to anterior and posterior margins and covered in sparse, fine tomentum. All margins slightly rounded. Posterior margin decorated with fine golden tomentum.

LEGS. Moderately long; hind femora up to 20% longer than body; hind tibiae up to 50% longer than body in both males and females. Coxae and trochanters mottled light and dark brown. Fore and mid femora and tibiae with conspicuous alternating light and dark bands. Hind femora variegated; hind tibiae of uniform dark colour. Fore coxae with a pronounced lateral spine. Fore femora often with one or two prolateral linear spines below, armed with one prolateral and one retrolateral spine at apex. Fore tibiae usually with three linear spines below on both anterior and posterior edges. Fore tibiae armed with two long spines below (one prolateral and one retrolateral) and two short spines above (one prolateral and one retrolateral) at apex. Mid femora without linear spines above or below, but with one prolateral and one retrolateral spine at apex. Mid tibiae generally with three linear spines below on both anterior and posterior edges. Mid tibiae armed with two long spines below (one prolateral and one retrolateral) and two short spines above (one prolateral and one retrolateral) at apex. Hind femora with four to eight small, retrolateral linear spines, up to two prolateral linear spines and armed with one retrolateral spine at apex. Hind tibiae with 25 to 36 linear spines of varying length above, on both anterior and posterior edges. Hind tibiae with two superior subapical spines (one prolateral and one retrolateral), two superior apical spines (one prolateral and one retrolateral), two inferior apical spines (one prolateral and one retrolateral) and two inferior subapical spines (one prolateral and one retrolateral). Superior subapical spines about as long as inferior apical spines and twice as long as inferior subapical spines; superior apical spines three to four times as long as inferior apical spines. Hind tarsi with four segments, first and second segments with a pair of spines on distal end. First segment with 6–15 small dorsal, alternate spines. Second segment with 2–7 small dorsal, alternate spines. Second and fourth segments approximately one third length of first segment and third segment one third length of second and fourth segments.

ABDOMEN. Colour variegated, mainly pale, but with at least one pair of black patches on every tergite and covered in sparse, fine tomentum. Dorsal median line generally visible but thin and not very pronounced. All tergites with a pattern of alternating pale and dark bars next to posterior margin, the latter covered with fine golden tomentum, like the pronotum, giving the animal quite a beautiful look.

MALE TERMINALIA. Cerci long, pointed at apex, dark brown in colour, clothed in setae. Styli short, extending about as far as end of subgenital plate. Subgenital plate ends with a strongly keeled triangle bent upwards ( Fig. 8M, O ).

FEMALE TERMINALIA. Subgenital plate strongly bilobed, its pointed lobes separated by a deep, U-shaped depression ( Fig. 10M ). Ovipositor reddish-brown, long (approximately as long as body length, and up to 20% longer) and relatively straight, but strongly recurved upwards near apex and terminating with a very sharp point. Upper valve smooth above, but lower valve with 5 to 7 strong teeth at apex on ventral edge ( Fig. 10 N–O). Dorsal view of terminalia as in P. simplex ( Fig. 12A ).

Figures

Fig. 2. Phylogenetic relationships of Pleioplectron Hutton, 1896 cave wētā based on mtDNA sequence. A. Bayesian analysis using a mtDNA sequence alignment of 1429 bp spanning the majority of COI, with a minimum individual sequence length of 1330. Posterior probabilities are shown by nodes. B. Maximum Likelihood tree using PhyML with a COI alignment that contained sequences ranging from 483bp to 1429 bp, although the majority were>850 bp at the 3′ end of the gene. C. Map of New Zealand entomological (Crosby) regions. These codes are indicated in the Material examined section for each species.

Fig. 15. Live Pleioplectron Hutton, 1896 in their natural environments. A. P. auratum sp. nov., adult ♂, Whites Beach, Rarangi. B. P. gubernator sp. nov., two adult ♂♂, Three Pointer, Gouland Downs, Heaphy Track. C. P. caudatum sp. nov., adult ♂, Blowfly Hut, Moeraki River, South Westland. D. P. flavicorne sp. nov., sub-adult ♀, Blowfly Hut, Moeraki River, South Westland. E–F. P. crystallae sp. nov. E. Adult ♂, Cave Brook, Gouland Downs, Kahurangi NP. F. Adult ♀ feeding on Racomitrium Brid. moss, Salisbury Lodge, Mt Arthur, Kahurangi NP.

Fig. 7. Left hind tibia of cave wētā in the genus Pleioplectron Hutton, 1896, dorsal view. A. P. simplex Hutton, 1896, adult ♀, Hinewai Reserve, Akaroa (MPN CW4114). B. P. hudsoni Hutton, 1896, adult ♂, Otaki Forks, Tararua Forest (MPN CW3890). C. P. thomsoni (Chopard, 1923) comb. nov., adult ♂, Claremont Bush Reserve, South Canterbury (MPN CW4115). D. P. triquetrum sp. nov., adult ♂, Hinau Track, Kaikōura (MPN CW3921). E. P. auratum sp. nov., adult ♂, Whites Beach, Rarangi (MPN CW4295). F. P. gubernator sp. nov., adult ♂, Lewis Pass (MPN CW4066). G. P. caudatum sp. nov., adult ♂, Moeraki River (MPN CW4239). H. P. flavicorne sp. nov., adult ♀, Brewster Hut Track, Haast Pass (MPN CW3896). I. P. crystallae sp. nov., adult ♂, Cave Brook, Gouland Downs (MPN CW3994). J. P. rodmorrisi sp. nov., adult ♂, Hodder River, Inland Kaikōura Range (MPN CW3819). Scale bar = 5 mm.

Fig. 8. Adult male terminalia of cave wētā in the genus Pleioplectron Hutton, 1896. Left column: ventral view (subgenital plate); central column: dorsal view; right column: lateral view. A–C. P. simplex Hutton, 1896, Hinewai Reserve, Banks Peninsula. A–B. MPN CW4109. C. MPN CW4118. D–F. P. hudsoni Hutton, 1896, Otaki Forks, Tararua Forest Park (MPN CW3890). G–I. P. thomsoni (Chopard, 1923) comb. nov., Trotters Gorge, Otago (MPN CW3780). J–L. P. triquetrum sp. nov., Hinau Track, Kaikōura. J, L. MPN CW3922. K. MPN CW3928. M–O. P. auratum sp. nov. M, O. Whites Beach, Rarangi (MPN CW4295). N. Waihopai River, Blenheim (MPN CW4146). Scale bars = 1 mm.

Fig. 10. Adult female terminalia of cave wētā in the genus Pleioplectron Hutton, 1896. Left column: subgenital plate; central and right columns: ovipositor. A–C. P. simplex Hutton, 1896, Hinewai Reserve, Banks Peninsula (MPN CW4114). D–F. P. hudsoni Hutton, 1896, Karori Ecosanctuary, Wellington. D. MPN CW3554. E–F. MPN CW3552. G–I. P. thomsoni (Chopard, 1923) comb. nov. G. Pioneer Park, Opihi River, South Canterbury (MAPN CW3913). H–I. Trotters Gorge, Otago (MPN CW4007). J–L. P. triquetrum sp. nov., Tweedies Gully, Gore Bay (MPN CW3846). M–O. P. auratum sp. nov., Renwick, Blenheim. M. MPN CW4120. N–O. MPN CW4119. Scale bars = 1 mm.

Fig. 12. Adult female terminalia of cave wētā in the genus Pleioplectron Hutton, 1896, dorsal view (suranal plate). A. P. simplex Hutton, 1896, Hinewai Reserve, Banks Peninsula (MPN CW4114). B. P. crystallae sp. nov., Salisbury Lodge, Mt Arthur (MPN CW3941). C. P. caudatum sp. nov., Brewster Hut Track, Haast Pass (MPN CW4040). Scale bars = 1 mm.