Diversity and distribution of Pleioplectron Hutton cave wētā (Orthoptera: Rhaphidophoridae: Macropathinae), with the synonymy of Weta Chopard and the description of seven new species

The genus Pleioplectron was first described by Hutton (1896) and included six New Zealand species. This genus has since had three species moved, one each to the genera Pachyrhamma Brunner von Wattenwyl, 1888, Miotopus Hutton, 1898 and Novoplectron Richards, 1958. Here we clarify the status and appearance of Pleioplectron simplex Hutton, 1896 (incl. P. pectinatum Hutton, 1896 syn. nov.) and P. hudsoni Hutton, 1896, as well as P. thomsoni (Chopard, 1923) comb. nov., which is transferred from the genus Weta Chopard, 1923. The genus Weta is newly synonymised with Pleioplectron. We also describe seven new species of Pleioplectron from South Island, New Zealand: P. auratum sp. nov., P. caudatum sp. nov, P. crystallae sp. nov., P. flavicorne sp. nov., P. gubernator sp. nov., P. rodmorrisi sp. nov and P. triquetrum sp. nov. We base these descriptions on morphology using fresh specimens of both male and female adults, and provide support for each with DNA sequence variation (mtDNA, partial COI).


Introduction
The systematics of New Zealand cave wētā at the generic and specifi c levels has been hampered by the limited number of accessible and diagnostically informative morphological characters and often brief original descriptions for many of the nineteen genera of New Zealand Rhaphidophoridae (Cook et al. 2010). The genus Pleioplectron is a case in point with several broad traits including size, overall   , v. small 2 (0-2) 7 (4-8) 1 The six numbers are, in order from left to right: fore femur prolateral and retrolateral, mid femur prolateral and retrolateral, hind femur prolateral and retrolateral. '1' means that an apical spine is present, '0' means that an apical spine is absent. Ratio hind tibia to body length   The six numbers are, in order from left to right: fore femur prolateral and retrolateral, mid femur prolateral and retrolateral, hind femur prolateral and retrolateral. '1' means that an apical spine is present, '0' means that an apical spine is absent.  Fitness et al. 2018). A reduced taxon dataset with just 19 putative specimens of Pleioplectron allowed Bayesian inference to assess the monophyly of the genus. The Bayesian analysis used a chain length of 4 million generations sampling every 2000, and with a burn-in of 100 000 generations. Maximum Likelihood was then used with mtDNA sequences from 88 putative specimens of Pleioplectron to test species hypotheses based on morphology and confi rm the association of males and females within each taxon.
Mitochondrial DNA sequence variation allowed us to verify prior hypotheses of distinct taxa based on morphological traits, and confi rm the association of male and female individuals collected at the same and different locations, including confi rmation for the fi rst time of females of Pleiplectron hudsoni. The correlation of morphological and genetic clusters is expected from distinct evolutionary lineages that are consistent with their treatment as distinct taxonomic units (Mallet 1995(Mallet , 2013. We note that large stable populations observed in New Zealand insect species tend to yield distributions of pairwise mtDNA differences that deviate from the expected exponential distribution owing to their common history (Slatkin & Hudson 1991;Morgan-Richards et al. 2017), which can mislead species delimitation tools that rely on this single non-recombining locus (Dellicour & Flot 2015).

Identity of previously described species
Using the morphology of terminalia in adult specimens and unique combinations of apical spines (Table 1), we identifi ed cave wētā that could be assigned to Pleioplectron hudsoni Hutton, 1896, P. simplex Hutton, 1896, Weta thomsoni Chopard, 1923 and seven other related species. Analysis of mtDNA COI sequence variation (Genbank accessions MK871355-MK871373) confi rmed the distinction between Pleioplectron and Miotopus (Fitness et al. 2018), and the monophyly of individuals assigned by morphological identifi cation to Pleioplectron hudsoni, P. simplex and Weta thomsoni (Fig. 2). Our mtDNA sequence analysis supported Richards (1958) in separating Novoplectron serratum (Hutton, 1904) from the genus Pleioplectron (Fig. 2B). The seven new species identifi ed by morphology were each found to correspond to a distinct mtDNA lineage within the monophyletic Pleioplectron (plus Weta) clade (Fig. 2).
Weta thomsoni presents several morphological characters that are similar to those of Pleioplectron simplex: the confi guration of the male terminalia, especially the shape of the suranal and subgenital plates; the shape of the ovipositor, smooth above and with strong teeth on the lower valve near the apex; the shape and confi guration of linear spines on the hind tibiae; and the structure of the hind tarsi, with long dorsal apical spurs and several small dorsal spines on fi rst and second tarsal segments. The ecology of the two species is also more similar than originally thought. While it was initially assumed that W. thomsoni lived only in caves, because this is where the type specimens were collected, we now know that it does in fact live in leaf litter on the forest fl oor of both native and exotic forests in South Canterbury and Otago, readily occupying caves wherever these are available. As W. thomsoni and Pleioplectron spp. are morphologically and genetically similar and Pleioplectron has chronological precedence over Weta, we consider that this species should now be referred to as Pleioplectron thomsoni (Chopard, 1923) comb. nov.
Given that Weta thomsoni is the type species for the genus Weta Chopard, 1923 None of the cave wētā specimens examined could be assigned to P. pectinatum Hutton, 1896. These include 17 specimens from two sites on Banks Peninsula, the type location for P. pectinatum. Distinguishing between P. simplex and P. pectinatum appears to be near impossible using the descriptions by Richards (1959). We examined the male type specimens of Pleioplectron simplex and P. pectinatum, stored in ethanol at the Canterbury Museum in Christchurch, New Zealand (Fig. 3, Table 2). While the specimens are not in perfect condition, the terminalia are preserved well enough for us to confi rm that all specimens do in fact belong to one species, P. simplex. The suranal plate appears to be identical in the lectotype male of P. simplex and the paratype male of P. pectinatum (compare Fig. 3B, E). The subgenital plates in the holotype specimen of P. pectinatum and in the lectotype male of P. simplex have the same tricuspidate shape (compare Fig. 3C, F). It appears that specimens that were assigned to P. pectinatum were distinguished only by having everted terminalia, as they would have during copulation. This is something that happens occasionally when cave wētā are euthanised in ethanol. Given that P. simplex is the type species for Pleioplectron, we have decided to keep this species name and re-allocate P. pectinatum as its junior synonym.
Our examination of specimens of Rhaphidophoridae from the North Island of New Zealand identifi ed a common species of small, dark, forest dwelling cave wētā. This species is consistent in morphology at all locations where we observed it from Bay of Plenty to Wellington. Adult males and females are often found together and they have the same apical leg spine combination ( Hutton's original description of P. hudsoni, with three pairs of apical spines on the hind tibia, and so does the male subgenital plate, which is slightly longer than broad in a cuspidate shape and is slightly keeled. Here we consider that the widespread North Island morph represents P. hudsoni, but the brevity of Hutton's original description (and the lack of females) justifi es its redefi nition for clarity. Given that the holotype specimen is missing (Richards 1959) and no other type material is available, we designate a male neotype for P. hudsoni.

Etymology
Not explained by Hutton. ʻPleiosʼ = ʻmanyʼ, ʻplectronʼ = ʻplectrumʼ in Greek (most likely an analogy for the dorsal spines on the hind tibiae, which are shaped like a plectrum). The hind tibiae are armed with many dorsal spines, more numerous than in other genera Hutton would have been familiar with. Pleioplectron is neuter gender.

Description
With ten species in the genus, it is diffi cult to isolate morphological characters that apply to every species of Pleioplectron. Here, we focus on characters that fi t either all species, or only some, but are not found in other genera, and comment further on the differentiation of Pleioplectron from other genera of New Zealand Rhaphidophoridae in the Discussion.
Small-to medium-sized cave wētā (body length of adults 8.5 to 20 mm) found mainly in leaf litter in forests, occasionally in caves or above the tree-line, on the two main islands of New Zealand.
Head broad, nearly oval. Scapes of antennae sexually dimorphic in all species, very broad in males, thinner in females (Fig. 4). Segments of antennae fi tted with sensory hairs in sexually mature males of three species (Pleioplectron simplex Hutton, 1896, P. rodmorrisi sp. nov. and P. triquetrum sp. nov.), a character not seen in other genera of Rhaphidophoridae (Fig. 5). Eyes approximately 1.2 mm across on longest dimension regardless of size of animal, strongly bulging and appearing disproportionately large in smaller species (compare Fig. 4A-B with Fig. 4C-D). Maxillary palps of varying length, with moderately dense covering of hair.
Dorsal body colour patchy or chequered brown in most species, light/tawny in one species (Pleioplectron thomsoni (Chopard, 1923) comb. nov.), very dark/nearly black in some others (P. gubernator sp. nov. and P. caudatum sp. nov.). Two species (P. rodmorrisi sp. nov. and P. crystallae sp. nov.) with more varied and vibrant colouration. Most species with a prominent yellow median line along length of dorsum (Fig. 6). Lateral edges of pronotum with a pronounced rim and bent upwards in all species.
Leg length varies strongly among species and between individuals within a species. In some species, males tend to have longer legs than females. The difference in leg length between sexes does generally not exceed 20%, and is mostly less important than individual variation. Apical spines: all species have one anterior spine at the apex of the fore femur; four out of ten species additionally have a posterior spine at the apex of the fore femur (Table 1). All species have both an anterior and a posterior spine at the apex of the mid femur. The hind femur has a retrolateral apical spine in fi ve out of ten species (Table 1). All species have four apical spines at the apex of both fore and mid tibia, and at the apex of the hind tibia a pair of dorsal apical spines, a pair of dorsal sub-apical spines and a pair of ventral apical spines. Four out of ten species additionally have a pair of ventral sub-apical spines at the apex of the hind tibia ( Table 1). The dorsal apical spines on the hind tibia are very long, generally at least twice or three times the length of ventral apical spines. Linear spines: fore and mid femur generally unarmed, except in Pleiplectron auratum sp. nov. and P. rodmorrisi sp. nov. Hind femur generally armed below; the number of spines varies both within and between species. Fore tibia always unarmed above; mid tibia generally unarmed above, except in Pleioplectron rodmorrisi sp. nov. Fore and mid tibia armed below, with one to three pairs of linear spines; the number varies both within and between species. The hind tibia is always armed above with two parallel rows of 20 or more (up to 50) linear spines; only P. crystallae sp. nov. has fewer than 20 dorsal spines in each row (Table 1). Linear spines on the hind tibiae are socketed but not articulated, very variable in size on the same animal, randomly smaller and larger without obvious pattern (Fig. 7). Additionally, two species (P. auratum sp. nov. and P. crystallae sp. nov.) have one or more (up to four) pairs of much larger, possibly articulated dorsal spines on the hind tibiae. Fore and mid tarsi: all segments unarmed. Hind tarsi: always armed above with a variable number of small spines on both the fi rst and the second tarsal segment. The spines on the hind tarsi are most often alternate, meaning that if a spine is on the posterior edge, there is no corresponding spine in the same position on the anterior edge, and vice versa.
Male and female terminalia are species specifi c (Figs 8-11), yet they have common structures and elements in all species except for Pleioplectron rodmorrisi sp. nov. The male suranal plate is generally square on the posterior edge and covers all genital structures above. The male subgenital plate varies in shape between triangular and tri-lobed, but is often short, exposing three complex layers of genital structures in a ventral view. The female subgenital plate is rounded, bi-lobed or tri-lobed, at times small and largely hidden by the last sternite. The upper valve of the ovipositor is smooth in all species of Pleioplectron; the lower valve has few (up to ten) strong, well visible teeth near the apex (Figs 10-11). Pleioplectron simplex Hutton, 1896: 233, pl. 13, fi gs 13-13e. Pleioplectron pectinatum Hutton, 1896: 234. syn. nov.

Diagnosis
A medium-sized cave wētā found in forested and urban areas in the southern South Island, east of the mountains, mainly in inland Canterbury and the east coast. It is very common in highly modifi ed environments, including around dwellings and fi rewood piles; Pleioplectron simplex is 'the' urban cave wētā of New Zealand's South Island. Being chequered grey-brown in colour, often with a prominent yellow median line running along the length of the dorsum, it could be most easily mistaken for P. thomsoni (Chopard, 1923) comb. nov., with which it is sympatric, and with P. triquetrum sp. nov. at the northern end of its distribution range. It is readily distinguished from both of these species by lacking a retrolateral apical spine on the fore femur. Pleioplectron simplex is generally darker in colour compared to P. thomsoni comb. nov. and lighter compared to P. triquetrum sp. nov.

Etymology
Not explained by Hutton; ʻsimplexʼ is Latin for ʻsimpleʼ or ʻplainʼ.  Originally described by Hutton (1896), the species was redescribed adequately by Richards (1959). A notable detail omitted by both Hutton (1896) and Richards (1959) is the presence of sensory hair tuffs on the antennal segments of some, but not all, sexually mature males (Fig. 5).

Material examined (see also
Male Pleioplectron simplex on Banks Peninsula tend to reach larger dimensions than elsewhere, but our genetic data provide no evidence that the Banks Peninsula population is distinct. Of fi ve adult males we measured from Banks Peninsula, the smallest (MPN CW4112) measured 16.3 mm in body length, 12% longer than the largest adult male we collected elsewhere (MPN CW4013 from Long Beach, Dunedin, 14.5 mm long). To avoid introducing geographical bias in our measurements, we only included one adult male P. simplex from Banks Peninsula in Table 1, which gives us an estimate for the maximum size of the species. Hutton, 1896

Diagnosis
A small brown cave wētā with a yellow median dorsal stripe or band, found in forests throughout the North Island, New Zealand. It could be most easily confused with Miotopus diversus (Hutton, 1896) or Neonetus variegatus Brunner von Wattenwyl, 1888, two species with which it is sympatric and shares the forest habitat. From both of these species it is distinguished by the lack of a posterior apical spine on the fore femur. Additionally, it is smaller than M. diversus and lacks dorsal linear spines on the mid tibia.

Etymology
Named after the New Zealand entomologist George V. Hudson , who collected the holotype specimen (a male) in Wellington (Richards 1959). According to Richards (1959), the holotype is now missing.  HEAD. Frons dark brown, covered with very sparse setae; vertex glabrous and of variegated colour. Eyes dark, bulging and large compared to size of head. Fastigium dark, with a white spot on either side. Scapes and peduncles pale and pilose; antennae reddish brown, covered in fi ne setae. Maxillary and labial palpi light brown, with fi ne tomentum.

Material examined (see also
THORAX. Pronotum variegated brown; dark with pale bars next to posterior margin; covered in sparse, fi ne tomentum. Pronounced yellow median line. All margins of pronotum slightly rounded. LEGS. Moderately long; hind femora of approximately equal length as body in both males and females. Hind tibiae 5% to 20% longer than body in females, 10% to 30% longer than body in males. Coxae and trochanters mottled light and dark brown. Fore and mid femora and tibiae with alternating conspicuous light and dark bands; hind legs variegated. 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 one linear spine on anterior edge, two 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 anterior edge, zero 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 often armed with one small retrolateral linear spine below on interior edge, but without apical spines. Hind tibiae armed with approximately 20 linear spines above, of varying length, on both anterior and posterior edges. Hutton (1896) described these as "eight outer and 12 inner spines, and several minute teeth between them". 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 as inferior apical spines. Hind tarsi with four segments, fi rst and second segments with a pair of spines on distal end. First segment with 7-11 small, alternate dorsal spines. Second segment with 2-4 small, alternate dorsal spines. Second and fourth segments one third of length of fi rst segment. Third segment one third of length of second and fourth segments.
ABDOMEN. Colour variegated brown, often with dark, nearly black patches on sides of second, fourth, fi fth and eighth tergites; covered in sparse, fi ne tomentum. Yellow median dorsal line usually pronounced, of varying width, occasionally as a yellow band occupying middle third of dorsum. MALE TERMINALIA. Cerci long, pointed at apex, brown in colour, clothed in setae. Styli short and broad at base, almost triangular, not extending beyond end of subgenital plate. Subgenital plate as wide as long in a triangular shape; terminates in a blunt point between styli; slightly keeled. Terminalia appear tricuspidate at apex when seen from above. FEMALE TERMINALIA. Subgenital plate with three rounded points, outer two wider at base and longer than middle one. Ovipositor brown, recurved above, tapering very gently until near apex; relatively short (approximately three quarters of body length). Upper valve smooth above; lower valve with 7 to 9 blunt teeth at apex on ventral edge. Dorsal view of terminalia as in Pleioplectron simplex (Fig. 12A).

Diagnosis
A medium-sized cave wētā with long legs, pale colour, pronotum and tergites glabrous and shiny. It is common and widespread in caves and forests in South Canterbury and Otago, New Zealand. It has prolateral and retrolateral apical spines on both fore and mid femur.

Etymology
Named in honour of Dr. J. Allan Thomson (1881Thomson ( -1928, director of the Dominion Museum, Wellington, who sent the type specimens to Chopard. It is not known whether Thomson collected the specimens himself, or whether they were given to him by someone else.
Material examined (see also

Description
The original description by Chopard (1923) is both detailed and accurate, and is complemented by excellent drawings that have stood the test of time (see Fig. 13). A redescription is not required.

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 ʻTrĭquĕtrusʼ 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 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 fi ne setae. Maxillari and labial palpi brown, with fi ne 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, fi ne 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, fi rst 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 fi rst 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, fi ne 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. 10K-L). Dorsal view of terminalia as in P. simplex (Fig. 12A).  (Chopard, 1923)

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
ʻAurātusʼ is Latin for 'adorned with gold', because of the fi ne golden hair that adorns the posterior margins of the insect's tergites.
Material examined (see also  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 fi ne setae. Maxillari and labial palpi light brown, with fi ne tomentum.

MEASUREMENTS. See
THORAX. Pronotum mottled with pale and dark patches, but dark with pale bars next to anterior and posterior margins and covered in sparse, fi ne tomentum. All margins slightly rounded. Posterior margin decorated with fi ne 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, fi rst 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 fi rst 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, fi ne 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 fi ne 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. 10N-O). Dorsal view of terminalia as in P. simplex (Fig. 12A). 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. 9A-C with 9D-F). Nymphs of P. gubernator sp. nov. have antennae with bright yellow scapes similar to those of P. fl avicorne sp. nov., but the two species are geographically well separated.

Etymology
ʻGŭbernātŏrʼ is Latin for 'helmsman', because of the very prominent fi n under the male subgenital plate (Fig. 9A, C), which resembles the rudder under a boat.
Material examined (see also 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 fi ne setae. Maxillari and labial palpi light, with fi ne tomentum. THORAX. Pronotum variegated brown, mainly dark, with a few pale patches, dark with pale bars next to posterior margin and covered in sparse, fi ne 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, fi rst 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 fi rst segment, third segment one third of length of second and fourth segments.
ABDOMEN. Colour variegated brown, very dark with black patches and with sparse, fi ne 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 fi n 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. 11B-C). Dorsal view of terminalia with a sharp point on last tergite, as in P. crystallae sp. nov. (Fig. 12B). The habitus is typical of Pleioplectron, chequered grey-brown in colour, with banded legs but overall dark and without a median dorsal line. At the northern end of its distribution range, it could easily be mistaken for P. gubernator sp. nov, which lacks the prominent 'tail stump'. An examination of the adult terminalia is required to reliably distinguish these two species (compare Fig. 9D-F with 9A-C). Around Haast Pass, P. caudatum sp. nov. is sympatric and shares the same microhabitat with P. fl avicorne sp. nov. The latter is of a lighter brown colour, has bright yellow scapes on the antennae and lacks the 'tail stump'.

Etymology
ʻCaudatumʼ is Latin for 'tailed', because of the protuberance on the last tergite in both sexes, which resembles a tail stump (Figs 9E, 12C).  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 fi ne setae. Maxillari and labial palpi light brown, with fi ne tomentum. THORAX. Pronotum variegated brown, mainly dark, with a few pale patches; dark with pale bars next to posterior margin; covered in sparse, fi ne 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 20% longer than body in both males and females. Coxae and trochanters mottled light and dark brown. Fore and mid femora and tibiae with alternating conspicuous light and dark bands; hind legs variegated. Fore coxae with a pronounced lateral spine. Fore femora without linear spines above or below; armed with one prolateral spine at apex. Fore tibiae armed below, generally with one (at most two) linear spines on anterior edge, two 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 with two linear spines below on both anterior and 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, but have one retrolateral apical spine. Hind tibiae with 25 to 30 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) and two inferior apical spines (one prolateral and one retrolateral). Superior subapical spines and inferior apical spines of approximately equal length, superior apical spines two to three times as long. Hind tarsi with four segments, fi rst and second segment with a pair of spines on distal end. First segment with 5-8 small dorsal, alternate spines. Second segment with 2-3 small dorsal, alternate spines. Second and fourth segments one third of length of fi rst segment, third segment one third of length of second and fourth segments.

MEASUREMENTS. See
ABDOMEN. Colour variegated brown, very dark with black patches and covered in sparse, fi ne tomentum. Dorsal median line absent. MALE TERMINALIA. Cerci long, pointed at apex, dark brown in colour, clothed in setae. Styli short, rounded and not visible from above. Subgenital plate short, broadly oval, with median indentation (Fig. 9D). Last tergite with a distinctive protuberance, resembling a tail stump, that gives this species its name. Folds at base of cerci also pointed on interior edge, giving terminalia shape of a trident when seen from above (Fig. 9E). FEMALE TERMINALIA. Subgenital plate broad and rounded (Fig. 11D). Ovipositor reddish brown, weakly recurved above at tip and relatively short (approximately 60% of body length). Upper valve smooth above, but lower valve with 9 shallow teeth on ventral edge at apex (Fig. 11E-F). Terminalia with a strong protuberance on last tergite when viewed from above, unique to this species (Fig. 12C). Pleioplectron fl avicorne sp. nov. is sympatric and shares the same microhabitat with P. caudatum sp. nov., but compared to the latter it is lighter brown in colour and lacks a 'tail stump'. Nymphs of P. gubernator sp. nov. have bright yellow scapes of the antennae as in P. fl avicorne sp. nov., but the two species are geographically well separated.

Etymology
ʻFlāvicornisʼ is Latin for 'yellow horned' in reference to the bright yellow scapes of the antennae (Figs 6I, 15D). Material examined (see also   Table 1. HEAD. Frons dark brown except for two white lateral patches; 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 bright yellow and pilose; antennae reddish brown, covered in fi ne setae. Maxillari and labial palpi mottled light brown, with fi ne tomentum.

MEASUREMENTS. See
THORAX. Pronotum mottled reddish brown/dark brown, with few pale patches; dark with pale bars next to posterior margin; covered in sparse, fi ne tomentum. All margins slightly rounded. LEGS. Moderately long; hind femora of approximately equal length as body; hind tibiae on average 15% longer than body in both males and females. Coxae and trochanters pale with dark patches. Fore and mid femora and tibiae with conspicuous alternating light and dark bands, and hind legs variegated. 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 linear spines on both anterior and posterior edge. Fore tibiae armed with two long spines below (one prolateral and one retrolateral) and two short superior spines (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 with up to two linear spines below on both anterior and 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 and at apex. Hind tibiae armed with 23 to 30 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) 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 twice as long. Hind tarsi with four segments, fi rst and second segment with a pair of spines on distal end. First segment with 7-10 small dorsal, alternate spines. Second segment with up to fi ve small dorsal, alternate spines. Second and fourth segments one third to one half of length of fi rst segment, third segment one third of length of second and fourth segments.
ABDOMEN. Colour variegated brown, mostly reddish brown with black patches and covered in sparse, fi ne tomentum. Dorsal yellow median line thin but generally pronounced and visible. MALE TERMINALIA. Cerci long, pointed at apex, brown in colour and clothed in setae. Styli short and not visible from above. Subgenital plate broad, oval (Fig. 9G). Suranal plate a tall truncated cone, almost half length of cerci, and covering styli and all genital organs entirely (Fig. 9H). FEMALE TERMINALIA. Subgenital plate tri-lobed, all lobes shallow and rounded (Fig. 11G). Ovipositor reddish brown, weakly recurved above at tip and relatively short (approximately three quarters of body length). Upper valve smooth above, but lower valve with 9 to 11 shallow teeth on ventral edge at apex (Fig. 11H-I). Terminalia similar to those of P. simplex when viewed from above (Fig. 12A).

Diagnosis
A small cave wētā from the northwestern regions of the South Island of New Zealand, found predominantly near the tree line and in sub-alpine habitats, on the forest fl oor or on tree trunks, where it feeds on Racomitrium Brid. moss and occasionally on lichens. Unmistakable in its looks, this striking species stands out for its four or fi ve pairs of very long, articulated spines on the hind tibiae, the chevron pattern on its back and a colour that varies from military green to brown and reddish brown. Because of its small size, the long spines on the hind tibiae and its preference for moss, it could be mistaken for Maotoweta virescens Johns & Cook, 2013, although it is larger, never bright green and the spines on the hind tibiae do look different when examined under the microscope.

Etymology
Named for Crystal Brindle, hut warden at Gouland Downs when the species was fi rst discovered.
Material examined (see also   Table 1. HEAD. Frons mottled, a mix of dark brown and yellow patches, with sparse setae; vertex glabrous and of variegated colour. Eyes reddish brown and bulging. Fastigium reddish brown, with a white spot on either side. Scapes and peduncles red with brown patches; antennae red, covered in fi ne setae. Maxillari and labial palpi mottled light brown, with fi ne tomentum (Fig. 4C-D).

MEASUREMENTS. See
THORAX. Pronotum mottled, red, red-brown, brown or military green; dark with pale bars next to anterior and posterior margins; covered in sparse, fi ne tomentum. Dorsal yellow median line generally pronounced. All margins are slightly rounded.  , 1842). B. Adult ♂. The different colouration is due to individual variation, not sexual dimorphism. C-D. P. thomsoni (Chopard, 1923) comb. nov. C. Adult ♂ in natural cave, Trotters Gorge, Otago. D. Adult ♀ in mining tunnel in Bannockburn, Central Otago, where a population of nearly white colour exists. E. P. hudsoni Hutton, 1896, adult ♀, Otaki Forks, Tararua Forest. F. P. triquetrum sp. nov., ♂, Hinau Track, Kaikōura. LEGS. Relatively short; hind femora generally shorter than body length. Hind tibiae up to 15% longer than body in females, up to 40% longer than body in males. Coxae and trochanters variegated. All legs red with inconspicuous brown patches or bands. 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 linear spines on anterior edge, 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, generally with two linear spines on anterior edge, one linear spine 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 armed below with up to fi ve very small, retrolateral, linear spines but unarmed at apex. Hind tibiae with 13 to 22 linear spines of varying length above on both anterior and posterior edges, including four or fi ve pairs of prominent, articulated spines, plainly visible to the naked eye (Fig. 7I). 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 twice as long. Hind tarsi with four segments, fi rst and second segment with a pair of spines on distal end. First segment with 5-11 small dorsal, alternate spines. Second segment with 1-4 small dorsal, alternate spines. Second and fourth segments one third to one half of length of fi rst segment; third segment one third of length of second and fourth segments.
ABDOMEN. Colour red, red-brown, brown or military green; covered in sparse, fi ne tomentum. Tergites adorned with a characteristic chevron or diamond pattern (Figs 6J, 15E-F). Dorsal yellow median line generally pronounced and well visible. MALE TERMINALIA. Cerci long, pointed at apex, variegated, clothed in setae. Styli very short, not visible from above. Subgenital plate with an orange protuberance shaped like a blunt blade with lateral swellings at its tip (Fig. 9J). Suranal plate square (Fig. 9K). FEMALE TERMINALIA. Subgenital plate with a single lobe (Fig. 11J). Ovipositor dark brown, tapering quickly near base, strongly recurved above at tip and on average about 80% as long as body. Upper valve smooth above, but lower valve with 6 to 9 strong teeth on ventral edge at apex (Fig. 11K-L). From above, terminalia appear to have a sharp point on last tergite (Fig. 12B).

Diagnosis
A medium-sized cave wētā that inhabits rock bluffs in the sub-alpine and low alpine regions of the Kaikōura Ranges and North Canterbury on South Island, New Zealand, up to an elevation of approximately 1500 m a.s.l. A strikingly beautiful and unmistakeable animal, it stands out for its unusually long legs (especially in the males), red-orange legs and antennae, purple-black back and a bold dorsal yellow median line.

Etymology
Named for Rod Morris, biologist and wildlife photographer, who fi rst discovered and documented the species in the Seaward Kaikōura Range in 1993.
Material examined (see also  Table 1. HEAD. Frons glabrous, pale pink-orange, with dark patches under eyes; vertex glabrous and of variegated colour. Eyes dark brown. Fastigium dark, with a white spot on either side, but yellow anteriorly. Scapes and peduncles orange-red and hairy; antennae orange-red, covered in fi ne setae. Maxillari and labial palpi pale, with fi ne tomentum. In sexually mature males some antennal segments may have sensory hair tufts as in P. simplex (see Fig. 5).

MEASUREMENTS. See
THORAX. Pronotum pink orange, with a prominent yellow median line, and black regions next to all margins; covered in sparse, fi ne tomentum. All margins slightly rounded. Anterior corners of pronotum rounded, posterior corners more angular.
LEGS. Very long, sexually dimorphic (see Fig. 17), longer in males than in females. Coxae and trochanters pale pink/orange. Fore and mid femora orange. Hind femora variegated, purple in proximal portion and Adult ♀. C. Box plot for the ratio of leg length/body length, by sex. A one-way ANOVA test on leg length by sex shows that all legs are signifi cantly longer in males than they are in females, with the following results: Fore leg: F = 198.5 on 1 and 13 degrees of freedom; P = 3 × 10 -9 ; R 2 = 0.9385. Mid leg: F = 130.9 on 1 and 13 degrees of freedom; P = 4 × 10 -8 ; R 2 = 0.9097. Hind leg: F = 16.18 on 1 and 13 degrees of freedom; P = 0.001; R 2 = 0.5545. orange in distal part; hind tibiae orange. Fore femora armed below with 3 to 8 needle-like, prolateral linear spines; armed with one prolateral and one retrolateral spine at apex. Fore tibiae generally 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 armed below with 1 to 9 prolateral and up to two needle-like, retrolateral linear spines and with one prolateral and one retrolateral spine at apex. Mid tibiae with three linear spines below on both anterior and posterior edges, and up to two linear spines above 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 armed below with 9 to 23 prolateral and 6 to 10 retrolateral linear spines. Hind tibiae with 30 to 46 small linear spines above on both anterior and posterior edges. Linear spines on hind tibiae more uniform in size than in other species of Pleioplectron (see Fig. 7J). 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 subapical spines and inferior apical spines about 50% longer, but twice as thick at base. Superior apical spines approximately twice as long as inferior apical spines. Hind tarsi with four segments, fi rst and second segment with a pair of spines on distal end. First segment with 6-14 small dorsal, alternate spines. Second segment with 1-6 small dorsal, alternate spines. Second and fourth segments approximately one third of length of fi rst segment, third segment one third of length of second and fourth segments.
ABDOMEN. Tergites pink/purple, black next to anterior and posterior margins; covered in sparse, fi ne tomentum. Dorsal yellow median line very pronounced and continuous all the way to last tergite. MALE TERMINALIA. Cerci long, pointed at apex, pale, clothed in setae. Styli short and thin, pale and hairy. A V-shaped structure connected by a membrane protrudes beyond both suranal and subgenital plates, well visible both from above and from below ( Fig. 9M-N). FEMALE TERMINALIA. Subgenital plate an inverted V, pointed (Fig. 11M). Ovipositor reddish-brown, short (approximately 60% of body length), curved upwards at apex, and terminating in a sharp point. Upper valve smooth above and lower valve with 6 to 8 very strong teeth on ventral edge at apex (Fig. 11N-O). Dorsal view of terminalia similar to that in P. simplex (Fig. 12A).

Distribution and habitat
Cave wētā in the genus Pleioplectron are common and widespread in all regions of New Zealand's two main islands, except for Fiordland (Fig. 18); however, species are partitioned geographically across the country.
Only one species, Pleioplectron hudsoni, is known on North Island. While we have examined specimens of P. hudsoni collected from Wellington to Bay of Plenty (Fig. 18A), photographs we have seen suggest that this species is also found in Coromandel and in Northland, making it ubiquitous on North Island. Pleioplectron hudsoni is a forest specialist and limited to low and mid elevations; it lives in leaf litter on the forest fl oor and is often found among tree roots, in piles of sticks or under logs. Females lay eggs in dirt or in rotting wood (Fig. 19).
A very different picture emerges on South Island, where at least nine species have evolved, each confi ned to a limited geographical region and specifi c habitat. While most South Island species also inhabit forest, two species (P. crystallae sp. nov. and P. rodmorrisi sp. nov.) have adapted to sub-alpine or alpine habitats. Several species readily use human-modifi ed habitats, and at least one species (P. thomsoni comb. nov.) is common in caves within its range.
Pleioplectron simplex is usually observed at night on the forest fl oor in both native forests and exotic plantations in Mid Canterbury and on Banks Peninsula. Of all cave wētā species in New Zealand it is the most commonly observed in urban habitats. Pleioplectron simplex is common in basements of houses and in fi rewood piles in all major towns on the east coast of South Island, between Christchurch and Invercargill. Several hundred specimens can be found in the basement of the caretaker's house at Hinewai Reserve on Banks Peninsula. A population has also established itself in sea caves at Long Beach, Dunedin.
Pleioplectron thomsoni comb. nov. seems to be at home in leaf litter in native forests and in exotic plantations throughout South Canterbury and Otago, as well as on the boulders and low cliff faces of inland South Canterbury and in the rocky landscapes of Central Otago's lowlands. It does, however, reach its highest densities in caves and abandoned mining and railway tunnels, where it often cooccurs with Rhaphidophoridae of the genus Macropathus Walker, 1869. Dense clusters of individuals are common on the ceiling of caves, with overlapping legs and antennae (Fig. 20). The population of P. thomsoni comb. nov. in abandoned gold mining tunnels in Silverpeaks, Dunedin, reaches the thousands; the fl oor of the mining tunnels is entirely covered by a layer of cave wētā frass. Pleioplectron thomsoni comb. nov. also tolerates human modifi ed habitats; it inhabits urban parks in Timaru, South Canterbury, and is occasionally spotted in fi rewood piles in Central Otago and in Mount Cook Village.
Pleioplectron triquetrum sp. nov. and P. auratum sp. nov. inhabit native and exotic forests in the northeast of South Island. Pleioplectron triquetrum sp. nov. is widespread in North Canterbury, South Marlborough and in the Kaikoura Region, whereas P. auratum sp. nov. seems to be confi ned to North Marlborough and to the Marlborough Sounds, south and east of Queen Charlotte Sound. The scarcity of caves within their distribution range means we do not know whether they would use cave habitat, but we did not fi nd P. auratum sp. nov. in caves near Rarangi, while we did fi nd it in native forest nearby. Pleioplectron auratum sp. nov. has been observed in human modifi ed habitats such as fi rewood piles, roadside stone walls and in fl ood debris at the edge of rivers.
Pleioplectron gubernator sp. nov., P. caudatum sp. nov. and P. fl avicorne sp. nov. are three apparently ecologically very similar species, adapted to life in the leaf litter of rain forests in the western regions of South Island. Their small size and dark colour, combined with their nocturnal habits typical of all cave wētā, make them well camoufl aged and hard to spot in their habitat. All three species are found from sea level right up to the tree line, and on at least one occasion we have found P. gubernator sp. nov. on leaves of mountain daisy (Celmisia Cass. spp.), one hundred metres above the tree line. Pleioplectron gubernator sp. nov. and P. caudatum sp. nov. have distinct distributions, north and south of the glaciers respectively. Pleioplectron fl avicorne sp. nov. is sympatric and shares the same microhabitat with P. caudatum sp. nov., and the two species are often found in mixed populations, although P. fl avicorne sp. nov. may be confi ned to a smaller region in the vicinity of Haast Pass. Caves and mining tunnels are common within the ranges of these three species, and are regularly inhabited by other Rhaphidophoridae, such as Miotopus richardsae Fitness et al., 2018, Macropathus fi lifer Walker, 1869and Pachyrhamma edwardsii (Scudder, 1869. We have never found Pleioplectron gubernator sp. nov., P. caudatum sp. nov. or P. fl avicorne sp. nov. in a cave or in a mining tunnel.
Pleioplectron crystallae sp. nov. is also a ground dweller, almost exclusively found feeding on Racomitrium Brid. moss and on lichens in the far north of South Island. It mainly lives at higher elevations, in forests near the tree line, or on vegetated cliffs in the sub-alpine zone. Our highest observation is on cliffs at 1400 m a.s.l. on Mount Peel in Kahurangi National Park. Notably, P. crystallae sp. nov. has four to fi ve pairs of prominent, long dorsal spines on the hind tibia, a trait it shares with another moss specialist, Maotoweta virescens Johns & Cook, 2013, in what appears to be a case of convergent evolution.
Pleioplectron rodmorrisi sp. nov. is possibly the most peculiar among Pleioplectron, having adapted to life on bare cliffs in the subalpine and low alpine regions in the northeast of the South Island, up to 1500 m a.s.l. At all sites, we have found it to coexist with Petrotettix serratus Richards, 1972, a typically alpine species. Our lowest observation of P. rodmorrisi sp. nov. is at 1150 m a.s.l., right at the tree line in the Hodder River, Inland Kaikoura Range, where it forms mixed populations with Pleioplectron triquetrum sp. nov. Fig. 19. Pleioplectron hudsoni Hutton, 1896. Live specimens in their natural environment. Zealandia Ecosanctuary, Wellington. A. Mating pair. As in most New Zealand Rhaphidophoridae, the female is on top. B. Adult ♀ egg-laying in rotting log.

Differentiation of Pleioplectron from other genera of Rhaphidophoridae in New Zealand
In the generic description we listed traits that are characteristic of Pleioplectron. Many of them, however, are not unique to Pleioplectron, and are not necessarily useful to differentiate it from other genera of New Zealand Rhaphidophoridae. Ward (1997) made a fi rst attempt at compiling a key to New Zealand genera of Rhaphidophoridae. He included the following features: apical spine count on fore, mid and hind femora; apical spine count on fore, mid and hind tibiae; shape of male subgenital plate; shape of female subgenital plate. Johns & Cook (2013) included a table as an appendix to their generic description of Maotoweta, in which they compared six genera of New Zealand Rhaphidophoridae based on the following traits: body length; apical spine count on fore, mid and hind femora; ventral linear spines on hind femora; dorsal linear spines on hind tibiae; apical spines on hind tibiae; hind tarsal plantulae; male subgenital plate; male suranal plate; female subgenital plate.
From our observations it is apparent that not all of these features are useful to characterise genera. The shape of male and female suranal and subgenital plates, for instance, used by both Ward (1997) and Johns & Cook (2013), is strongly species specifi c, and while it certainly is most useful when trying to differentiate between species, it is too variable within a genus to be helpful for identifi cation at the generic level, with the possible exception of Pachyrhamma Brunner von Wattenwyl, 1888. The same can be said about body length. Even less useful are apical spines on the hind femora and the ventral linear spines on the hind femora, two traits that we have found to be not even species specifi c (see also Cook et al. 2010;Fitness et al. 2015).  (Chopard, 1923) comb. nov. on cave ceiling. Trotters Gorge, Otago.
European Journal of Taxonomy 577: 1-46 (2019) 44 While our observations mostly align with those of Ward (1997) and Johns & Cook (2013), there are nonetheless some differences. Ward (1997), for instance, described the female subgenital plate in Weta Chopard, 1923 as "small, notched", with a matching illustration. In contrast, what we have observed (Fig. 10G) is in close agreement with the original description by Chopard (1923): "subgenital plate very small, almost hidden between the seventh sternite and the base of the ovipositor, rounded or little notched at the apex". Table 1 in Johns & Cook (2013) also seems to contain some inconsistencies, as Pleioplectron simplex and P. thomsoni comb. nov., for instance, are both described as having tarsal pads "bordered by spinules". We can clearly see these in the latter species, but not in the former. On the other hand, Johns & Cook (2013) reported the occasional presence of a retrolateral apical spine on the hind femur in P. thomsoni comb. nov., not in P. simplex or in Talitropsis sedilloti Bolivar, 1882. We have consistently found a retrolateral apical spine on the hind femur to be present in all three species. Johns & Cook's (2013) description of the dorsal spines on the hind tibiae of Pleioplectron simplex, "2 or 3 pairs immoveable socketed spines, 5-10 pairs fi xed spines," is also in disagreement with our spine count (20 to 33 prolateral, 23 to 35 retrolateral; see Table 1) or that of Richards (1959) (25-32 prolateral, 24-29 retrolateral). In the original description of Pleioplectron simplex, Hutton (1896) reported about 29 prolateral and 17 retrolateral dorsal spines on the hind tibiae. In agreement with Richards (1959), we assume the 17 to be a typographic error, 27 being the correct number, since the numbers of prolateral and retrolateral dorsal spines always closely match each other in all species of cave wētā.
While we note the inadequacy of the generic keys offered by Ward (1997) and by Johns & Cook (2013) in respect to Pleioplectron, we consider it premature to present an alternative one, without fi rst having discussed in detail other genera of New Zealand Rhaphidophoridae.
A detail that has received little attention so far in the study of New Zealand Rhaphidophoridae is the structure of the antennae. The sensory hair tufts on the antennae of some (but not all) adult male Pleioplectron appear to be unique to this genus, and different from the antennal structures in Pachyrhamma Brunner von Wattenvyl, 1888 (Fea et al. 2019). While their precise function is currently unknown, typically, the sexually dimorphic structures of insect antennae have the purpose of increasing surface area for sensory perception in males (Fea et al. 2019).