Pleioplectron gubernator, 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 : 24-28

Pleioplectron gubernator sp. nov.

urn:lsid:zoobank.org:act:50773A0B-37C2-47E8-887D-10A11B27FF57

Figs 2 A–B, 6C, 7F, 9A–C, 11A–C, 15B, 16, 18F

Diagnosis

A small inhabitant of the forest floor in the northwest of the South Island of New Zealand. The habitus is typical of Pleioplectron , chequered grey-brown in colour, with visibly banded legs. Very dark all over, with median dorsal line hardly visible. In Westland it could easily be mistaken for P. caudatum sp. nov., which lives further south along the coast. Examination of the terminalia is required to reliably distinguish the two species (compare Fig. 9 A–C with 9D–F). Nymphs of P. gubernator sp. nov. have antennae with bright yellow scapes similar to those of P. flavicorne sp. nov., but the two species are geographically well separated.

Etymology

ʻ Gŭbernātŏr ʼ is Latin for ‘helmsman’, because of the very prominent fin under the male subgenital plate ( Fig. 9A, C ), which resembles the rudder under a boat.

Material examined (see also Table 7 in Supplementary Material)

Holotype

NEW ZEALAND • ♂, adult; Buller (BR), Lewis Pass, Cannibal Gorge; 42.339893° S, 172.42208° E; 840 m a.s.l.; 3 Feb. 2017; Danilo Hegg leg.; in rotting tree stump in native forest; night search + insect net; NMNZ AI.037484 (prev. MPN CW4063 ).

Paratype

NEW ZEALAND • ♀, adult; Nelson (NN), Abel Tasman National Park, Awapoto Hut ; 40.86314° S, 172.9391° E; 660 m a.s.l.; 12 Oct. 2017; Danilo Hegg leg.; in roots of fallen tree; night search + insect net; NMNZ AI.037485 (prev. MPN CW4057 ) .

Other examined

NEW ZEALAND – Nelson (NN) • 1 ♀; East Takaka ; 40.92435° S, 172.85541° E; 600 m a.s.l.; 29 Jan. 2006; M. Morgan-Richards and S. Trewick leg.; on ground under beech tree; night search; MPN CW298 • 1 nymph; same collection data as for paratype; MPN CW3787 • 1 ♂; Heaphy Track, Perry Saddle ; 40.90029° S, 172.40416° E; 900 m a.s.l.; 19 Apr. 2016; D. Hegg leg.; under boulder on side of track; night search; MPN CW2986 • 1 ♂; Heaphy Track, Perry Saddle ; 40.90029° S, 172.40416° E; 900 m a.s.l.; 24 Dec. 2016; D. Hegg leg.; in leaf litter on forest floor; night search + insect net; MPN CW4075 • 2 ♂♂; Heaphy Track, Gouland Downs, Cave Brook ; 40.89240° S, 172.35540° E; 600 m a.s.l.; 26 Dec. 2016; D. Hegg leg.; on forest floor; night search + insect net; MPN CW4073 , CW4074 • 1 ♀; Heaphy Track, Gouland Downs, Cave Brook ; 40.89240° S, 172.35540° E; 600 m a.s.l.; 4 Feb. 2018; D. Hegg leg.; on forest floor; night search + insect net; MPN CW4058 • 1 ♂; Heaphy Track, Gouland Downs, Three Pointer ; 40.88383° S, 172.30983° E; 750 m a.s.l.; 22 Apr. 2016; D. Hegg leg.; on tree trunk; night search; MPN CW2980 • 1 ♀; Mt Arthur Tablelands, Salisbury Lodge ; 41.18511° S, 172.64465° E; 1150 m a.s.l.; 8 Feb. 2018; D. Hegg leg.; on tree trunk; night search + insect net; MPN CW4056 • 1 ♂; Mt Owen, Bulmer Creek ; 41.57134° S, 172.52491° E; 1000 m a.s.l.; 7 Jan. 2019; D. Hegg leg.; at base of tree; night search + insect net; MPN CW4262 • 1 ♂; Mt Owen, Branch Creek Hut; 41.52465° S, 172.51128° E; 920 m a.s.l.; 11 Jan. 2019; D. Hegg leg.; on tree trunk; night search + insect net; MPN CW4276 • 3 ♀♀; Mt Owen, Fyffe River ; 41.58800° S, 172.49235° E; 600 m a.s.l.; 12 Jan. 2019; D. Hegg leg.; rotting tree stump in forest; night search + insect net; MPN CW4277 to CW4279 . – Buller (BR) • 1 ♂, 1 ♀; Lewis Pass ; 42.37782° S, 172.40297° E; 850 m a.s.l.; 26 Apr. 2016; D. Hegg leg.; stream bank; night search; MPN CW2995 , CW2996 • 1 ♂, 2 nymphs; Lewis Pass ; 42.37782° S, 172.40297° E; 850 m a.s.l.; 23 Dec. 2016; D. Hegg leg.; rotting tree stump in forest; night search + insect net; MPN CW4059 to CW4061 • 4 ♂♂, 2 ♀♀; Lewis Pass ; 42.37782° S, 172.40297° E; 850 m a.s.l.; 10 Jan. 2017; D. Hegg leg.; rotting tree stump in forest; night search + insect net; MPN CW4065 to CW4068 , CW4071 , CW4072 • 1 ♂, 2 ♀♀; same collection data as for holotype; MPN CW4064 , CW4069 , CW4070 • 1 ♂, 3 ♀♀; Lewis Pass, Nina Valley ; 42.46601° S, 172.32211° E; 750 m a.s.l.; 26 Jan. 2018; D. Hegg leg.; on forest floor; night search + insect net; MPN CW4037 to CW4039 , CW4062 • 1 nymph; Charleston, Darkies Terrace ; 41.90941° S, 171.45284° E; 40 m a.s.l.; 18 Oct. 2018; D. Hegg leg.; at base of tree; night search + insect net; MPN CW4117 • 1 ♂, 1 ♀, 3 nymphs; Paparoa Range, Buckland Peaks ; 41.87418° S, 171.62879° E; 1040 m a.s.l.; 8 Dec. 2018; D. Hegg leg.; on forest floor; night search + insect net; MPN CW4251 to CW4253 , CW4266 , CW4280 • 1 nymph; Paparoa Range, Buckland Peaks ; 41.87526° S, 171.62669° E; 1150 m a.s.l.; 8 Dec. 2018; D. Hegg leg.; on Celmisia leaf, above tree line; night search + insect net; MPN CW4227 • 1 ♂, 1 nymph; Punakaiki, Truman Track ; 42.09270° S, 171.34071° E; 40 m a.s.l.; 6 Dec. 2018; D. Hegg leg.; in roots of fallen tree; night search + insect net; MPN CW4240 , CW4264 • 1 ♂, 2 ♀♀; Paparoa Range, Blackball Creek ; 42.32962° S, 171.39728° E; 300 m a.s.l.; 4 Apr. 2019; D. Hegg leg.; on bank on side of track; night search + insect net; MPN CW4327 to CW4329 . – Westland (WD) • 1 ♂; Hokitika, Awatuna, Havill Drive ; 42.64646° S, 171.06245° E; 20 m a.s.l.; 24 Apr. 2012; B. Taylor-Smith leg.; MPN CW2010 .

Description

MEASUREMENTS. See Table 1.

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

THORAX. Pronotum variegated brown, mainly dark, with a few pale patches, dark with pale bars next to posterior margin and covered in sparse, fine tomentum. Anterior and lateral margins slightly rounded; posterior margin nearly straight.

LEGS. Moderately long; hind femora of approximately equal length as body; hind tibiae on average 25% 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 dark brown. Fore coxae with a pronounced lateral spine. Fore femora without linear spines above or below, but armed with one prolateral spine at apex. Fore tibiae armed below, generally with two (sometimes three) linear spines on anterior edge, and one linear spine 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 anterior edge and one to two linear spines on posterior edge. 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 unarmed below. Hind femora armed with one retrolateral apical spine in specimens collected at Gouland Downs, but apical spines absent in specimens collected elsewhere. Hind tibiae with 20 to 29 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) and two inferior apical spines (one prolateral and one retrolateral). Superior subapical spines and inferior apical spines of approximately equal length, superior apical spines approximately three times as long. Hind tarsi with four segments, first and second segments with a pair of spines on distal end. First segment with 5–12 small dorsal, alternate spines. Second segment with 1–4 small dorsal, alternate spines. Second and fourth segments one third of length of first segment, third segment one third of length of second and fourth segments.

ABDOMEN. Colour variegated brown, very dark with black patches and with sparse, fine tomentum. Dorsal yellow median line absent or very thin.

MALE TERMINALIA. Cerci long, rounded at apex, dark brown in colour, clothed in setae. Styli very short and not visible from above. Subgenital plate very long, protruding through heavily deformed last two sternites, with a thin, translucent but very pronounced fin that gives this species its name ( Fig. 9A, C ). This feature is missing in specimens collection in the Paparoa Range, and the posterior part of the subgenital plate is covered by undeformed sternites ( Fig. 16 ). Structure of male terminalia otherwise the same. Suranal plate a tall truncated cone almost half length of cerci, covering styli and all genital organs entirely ( Fig. 9B ).

FEMALE TERMINALIA. Subgenital plate tri-lobed, with middle lobe pointed, two outer lobes broad and rounded ( Fig. 11A ). Ovipositor reddish brown, recurved above near tip, terminating in a very sharp point; approximately 80% of body length. Upper valve smooth above; lower valve with 8 to 12 small but strong teeth at apex on ventral edge ( Fig. 11 B–C). Dorsal view of terminalia with a sharp point on last tergite, as in P. crystallae sp. nov. ( Fig. 12B ).

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. 9. 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. gubernator sp. nov., Lewis Pass. A. MPN CW4063. B. MPN CW4067 C. MPN CW4059. D–F. P. caudatum sp. nov., Brewster Hut Track, Haast Pass (MPN CW4053). G–I. P. flavicorne sp. nov., Brewster Hut Track, Haast Pass (MPN CW4055). J–L. P. crystallae sp. nov., Cave Brook, Gouland Downs, Heaphy Track. J. MPN CW3994. K–L. MPN CW3995. M–O. P. rodmorrisi sp. nov., Kahutara Saddle, Seaward Kaikōura Range. M. MPN CW3536. N–O. MPN CW3395. Scale bars = 1 mm.

Fig. 16. Pleioplectron gubernator sp. nov., adult ♂♂, ventral view of subgenital plate in two populations. A. Lewis Pass (MPN CW4063). B. Punakaiki (MPN CW4264). Scale bar = 1 mm.

Fig. 11. Adult female terminalia of cave wētā in the genus Pleioplectron Hutton, 1896. Left column: subgenital plate; central and right columns: ovipositor. A–C. P. gubernator sp. nov. A. Awapoto Hut, Abel Tasman NP (MPN CW4057). B–C. Lewis Pass (MPN CW4071). D–F. P. caudatum sp. nov., Brewster Hut Track, Haast Pass (MPN CW4040). G–I. P. flavicorne sp. nov., Brewster Hut Track, Haast Pass (MPN CW4042). J–L. P. crystallae sp. nov., Cave Brook, Gouland Downs, Heaphy Track. J. MPN CW3993. K–L. MPN CW3990. M–O. P. rodmorrisi sp. nov., Hodder River, Inland Kaikōura Range (MPN CW3822). 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.