Pleioplectron triquetrum Hegg & Morgan-Richards & Trewick 2019, sp. nov.
Creators: name: Hegg, Danilo
name: Morgan-Richards, Mary
name: Trewick, Steven A.
Publisher: name: Zenodo
Year: 2019
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Orthoptera
Rhaphidophoridae
Pleioplectron
Pleioplectron triquetrum

description: Pleioplectron triquetrum sp. nov.
urn:lsid:zoobank.org:act: 75D542D6-516C-4905-ABE0-3F14A89DCE72
Figs 2 A–B, 6D, 7D, 8J–L, 10J–L, 14F, 18D
Diagnosis
A small to medium-sized, dark-coloured inhabitant of the forests in the northeast of the South Island of New Zealand. The habitus is typical of Pleioplectron, chequered grey-brown in colour, with visibly banded legs and often with a dorsal median line. At the southern end of its range (Canterbury /North Canterbury), it could be most easily confused with P. simplex Hutton, 1896, from which it is distinguished by the presence of a retrolateral apical spine on the fore femur, the darker colour and slightly smaller size. In northern Marlborough, it is most easily mistaken for P. auratum sp. nov., which is generally of lighter colour, but an examination of the terminalia is required to reliably distinguish the two species. Further inland and west, it could be confused with P. gubernator sp. nov., a smaller species that lacks the retrolateral apical spine on the fore femur.
Etymology
ʻ Trĭquĕtrus ʼ is Latin for ʻthree-corneredʼ or ʻtriangularʼ, after the triangular shape of the subgenital plate in the adult males (Fig. 8J).
Material examined (see also Table 5 in Supplementary Material)
Holotype NEW ZEALAND • ♂, adult; Kaikōura (KA), Hinau Track; 42.349586° S, 173.566727° E; 200 m a.s.l.; 22 Oct. 2016; Danilo Hegg leg.; at base of tree in native forest; night search + insect net; NMNZ AI.037480 (prev. MPN CW3922).
Paratype NEW ZEALAND • ♀, adult; North Canterbury (NC), Gore Bay, Tweedies Gully; 42.862247° S, 173.3073717° E; 40 m a.s.l.; 7 Apr. 2018; Danilo Hegg leg.; on clay bank on side of track in native forest; night search + insect net; NMNZ AI.037481 (prev. MPN CW3846).
Other material
NEW ZEALAND – Marlborough (MB) • 2 ♂♂, 2 ♀♀; Hanmer Springs, Fir Trail; 42.50273° S, 172.84644° E; 500 m a.s.l.; 20 Dec. 2005; J. Goldberg and F. Wieland leg.; MPN CW386 to CW389. – Kaikōura (KA) • 1 ♂, 2 ♀♀, 1 nymph; Hodder River; 41.95700° S, 173.65023° E; 1150 m a.s.l.; 6 Apr. 2018; D. Hegg leg.; under boulders at bush-line; night search + insect net; MPN CW3826, CW3827, CW3858, CW3916 • 1 ♂, 2 ♀♀; same collection data as for holotype; 28 Mar. 2016; MPN CW2870 to CW2872 • 1 ♂, 1 ♀, 2 nymphs; same collection data as for holotype; MPN CW3921, CW3923, CW3924, CW3972 • 2 ♂♂, 1 ♀; same collection data as for holotype; 1 Apr. 2017; MPN CW3928, CW3929, CW3970. – North Canterbury (NC) • 3 ♂♂, 2 ♀♀, 1 nymph; same collection data as for paratype; MPN CW3839 to CW3841, CW3844, CW3845, CW3920 • 3 nymphs; Waipara, Tiromoana Bush Walk; 43.09836° S, 172.84595° E; 150 m a.s.l.; 27 Sep. 2018; D. Hegg leg.; on clay bank on side of track; night search + insect net; MPN CW4084 to CW4086.
Description
MEASUREMENTS. See Table 1.
HEAD. Frons dark brown, with very sparse setae; vertex glabrous and of variegated colour. Eyes dark. Fastigium dark, with a white spot on either side. Scapes and peduncles pale and pilose; antennae dark with occasional pale segments, covered in fine setae. Maxillari and labial palpi brown, with fine tomentum. In some sexually mature males, antennal segments have sensory hair tuffs as in P. simplex (see Fig. 5).
THORAX. Pronotum variegated dark brown with pale patches; dark with pale bars next to anterior and posterior margins; covered in sparse, fine tomentum. Anterior and lateral margins slightly rounded; posterior margin nearly straight.
LEGS. Moderately long; hind femora 10% to 20% longer than body in both males and females; hind tibiae 10% to 30% longer than body in females, 20% to 50% longer than body in males. 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 uniform dark colour. Fore coxae with a pronounced lateral spine. Fore femora without linear spines above or below but armed with one prolateral and one retrolateral spine at apex. Fore tibiae armed below, generally with two (up to four) linear spines on anterior edge and three (two to four) linear spines on posterior edge. 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 armed with one prolateral and one retrolateral spine at apex. Mid tibiae armed below, with one to three linear spines 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 armed with three to seven very small retrolateral linear spines below, and one retrolateral apical spine. Hind tibiae armed with 21 to 33 linear spines above, of varying length, 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 twice as long as inferior subapical spines, inferior apical spines twice as long again; superior apical spines approximately three 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 7–13 small dorsal, alternate spines. Second segment with 3–9 small dorsal, alternate spines. Second and fourth segments of approximately half of length of first segment, third segment one third of length of second and fourth segments.
ABDOMEN. Colour variegated brown/black, with a few lighter patches; covered in sparse, fine tomentum. Dorsal median line generally visible but thin and not very pronounced (Figs 6D, 14F).
MALE TERMINALIA. Cerci long, pointed at apex, dark brown colour, clothed in setae. Styli short and stumpy, extending about as far as end of subgenital plate. Subgenital plate forms a neat triangle, not keeled (Fig. 8J). Apex of subgenital plate visible from above, looking like a small alpine hat (Fig. 8K).
FEMALE TERMINALIA. Subgenital plate weakly bilobed, its lobes separated by a very shallow depression (Fig. 10J). Ovipositor reddish-brown, strongly curved upwards at apex, terminating in a very sharp point; relatively short (approximately three quarters of body length). Upper valve smooth above; lower valve with 4 to 6 strong teeth at apex on ventral edge (Fig. 10 K–L). Dorsal view of terminalia as in P. simplex (Fig. 12A).
description: Published as part of 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, pp. 1-46 in European Journal of Taxonomy 577 on pages 19-20, DOI: 10.5852/ejt.2019.577, http://zenodo.org/record/3552088