Revision of the New Zealand cave wētā genus Isoplectron Hutton (Orthoptera: Rhaphidophoridae), with synonymy of Petrotettix Richards and Setascutum Richards, and the description of a new genus Author Hegg, Danilo 34DFC18A-F53D-417F-85FC-EF514F6D2EFD Wētā Conservation Charitable Trust, 135 Blacks Road, Ōpoho, Dunedin 9010, New Zealand. danilo@wetaconservation.org.nz Author Morgan-Richards, Mary 48F2FB1A-4C03-477C-8564-5417F9739AE1 Wildlife & Ecology Group, Massey University, Private Bag 11 - 222, Palmerston North 4442, New Zealand. M.Morgan-Richards@massey.ac.nz Author Trewick, Steven A. 7A378EE1-BADB-459D-9BAA-7059A675F683 Wildlife & Ecology Group, Massey University, Private Bag 11 - 222, Palmerston North 4442, New Zealand. S.Trewick@massey.ac.nz text European Journal of Taxonomy 2024 2024-12-10 971 1 75 https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/2761/12643 journal article 10.5852/ejt.2024.971.2761 2118-9773 14451786 F82472D1-595D-4DB7-A463-513B94BE85D9 Isoplectron bicolor sp. nov. urn:lsid:zoobank.org:act: EBEFE4F1-4F9B-4173-AF54-A53151132217 Figs 3 , 8 , 10E , 12C , 13C , 14G–I , 17G–I , 21E–F Diagnosis The largest species in the genus Isoplectron ; in the adult form, it is unmistakeable due to its characteristic coloration, with tawny head, thorax, fore and mid legs and hind femora, which contrast with the near black abdomen and hind tibiae ( Fig. 21E ). Nymphs could be easily mistaken for those of I. ferratum sp. nov. , with which it is sympatric, and with I. armatum . The latter species however is not found within the distribution range of I. bicolor sp. nov. Etymology ‘ Bĭcŏlor ’ (adj.) is Latin for ‘two-coloured’ – because of the unique contrasting coloration, tawny in the front and black in the back. Material examined (see also Supp. file 1: Table S3) Holotype NEW ZEALAND • ♂ , adult ; Nelson (NN), Cave Brook , Gouland Downs ; 40.89153° S , 172.35449° E ; 620 m a.s.l. ; 4 Feb. 2018 ; D. Hegg leg.; on tree trunk ; night search + insect net ; NMNZ AI.071889 . Paratype NEW ZEALAND • 1 ♀ , adult ; Nelson (NN), Chaffey Hut , Cobb River ; 41.09600° S , 172.57535° E ; 880 m a.s.l. ; 26 Dec. 2020 ; D. Hegg leg.; on tree trunk ; night search + insect net ; NMNZ AI.071890 . Other material NEW ZEALAND – Buller (BR) • 1 ♀ ; Nina Hut , Nina Valley ; 42.46573° S , 172.32202° E ; 760 m a.s.l. ; 15 Mar 2015 ; in sink outside hut ; photograph only; iNaturalist 1909084. – Nelson (NN) • 1 nymph; same data as for holotype; 20 Apr. 2016 ; GenBank: PP155151 ; MPN CW2991 • 1 ♂ ; same data as for holotype; GenBank: PP155152 ; MPN CW3758 • 1 ♂ ; Mt Arthur Tablelands ; 41.18500° S , 172.64370° E ; 1180 m a.s.l. ; 8 Feb. 2018 ; D. Hegg leg.; in beech tree canopy; night search + insect net ; GenBank: PP155153 ; MPN CW3760 • 1 ♂ ; same data as for preceding; 24 Dec. 2020 ; MPN CW5346 • 3 nymphs; same data as for paratype; MPN CW5195 , CW5197 , CW5198 • 1 ♂ ; same data as for paratype; 5 Jan. 2022 ; MPN CW5357 . Description MEASUREMENTS . See Table 1 . The only female collected has a body longer than any of the examined males by two to six millimetres. HEAD . As per generic description. Vertex tawny with dark streaks. A dark patch extends behind the posterior margin of the eye. Frons pale, with dark vertical stripes below the scapes of the antennae. Scapes of antennae tawny. All other segments of the antennae are reddish. THORAX . Pronotum, mesonotum and metanotum tawny with complex dark pattern ( Fig. 12C ). LEGS . All leg segments are tawny, except for the hind tibiae, which are near black in adults. Hind tibiae of same length as body in females, up to 50% longer than body in males. Fore femora always unarmed at the apex. Mid femora armed with one retrolateral spine at the apex; prolateral apical spine absent. Hind femora armed with nine to seventeen prolateral ventral linear spines, very small, and four to eight strong retrolateral ventral linear spines. Fore tibiae armed with two pairs of ventral linear spines, and with one pair of ventral apical spines. Mid tibiae armed with two pairs of ventral linear spines, one pair of ventral spines and one retrolateral dorsal spine at the apex. A prolateral dorsal spine at the apex of the mid tibia is always absent. Hind tibiae armed with 12 to 16 dorsal linear spines on both the anterior and the posterior edge ( Fig. 13C ). Hind tibiae armed at the apex with two ventral sub-apical spines, two ventral apical spines, two dorsal apical spines and two dorsal sub-apical spines. The dorsal apical spines are always largest, whereas the ventral sub-apical spines are smallest. First hind tarsal segment occasionally armed with a few dorsal linear spines. Second tarsal segment unarmed except at the apex. Fig. 17. Adult female terminalia of cave wētā in the genus Isoplectron Hutton, 1896 . Left column: subgenital plate; central and right columns: ovipositor. A–C . Isoplectron armatum armatum Hutton, 1896 . South Mavora Lake (MPN CW4927). D–F . I. armatum aciculatum Karny, 1937 . Ohakune. D . MPN CW5648. E–F . MPN CW5650. G– I . I. bicolor sp. nov. , paratype (NMNZ AI.071890). Chaffey Hut, Cobb River. J–L . I. pallidum ( Richards, 1972 ) comb. nov. Duffers Saddle, Old Woman Range (MPN CW5387). Scale bars: 1 mm. ABDOMEN . Typically dark, near black in adults, although a tawny diamond may extend from the thorax into the first few tergites ( Figs 12C , 21E ). Nymphs often have a diamond pattern on the back ( Fig. 21F ). Fig. 18. Adult female terminalia of cave wētā in the genus Isoplectron Hutton, 1896 . Left column: subgenital plate; central and right columns: ovipositor. A–C . Isoplectron serratum ( Richards, 1972 ) . Kahutara Saddle, Seaward Kaikōura Range ( MPN CW5555). D–F . I. maculatum sp. nov. Middle Mount Peel, South Canterbury (MPN CW5642). G–I . I. virgatum sp. nov. , paratype. Ces Clarke Hut, Paparoa Range (NMNZ AI.071895). J–L . I. ferratum sp. nov. , paratype. Mt Stokes, Marlborough Sounds (NMNZ AI.071897). Scale bars: 1 mm. MALE TERMINALIA . Subgenital plate with central lobe at least twice as long as lateral lobes, glabrous, with visible keel at centre ( Fig. 14H ). Cerci with alternating tawny and dark bands; on average one quarter of body length; covered in long hairs; tapering gradually along their whole length and ending with a blunt tip at the apex. Styli slender, covered in sparse setae, extending beyond the apex of the subgenital plate. Paraprocts with pronounced lateral lobes at the apex, which is covered in dense, stout spinules ( Fig. 14G ). The paraprocts project beyond the apex of the subgenital plate and are therefore visible from below ( Fig. 14H ). Fig. 19. Adult female terminalia of cave wētā in the genera Isoplectron Hutton, 1896 and Praecantrix gen.nov. Left column:subgenital plate; central and right columns:ovipositor. A–C . Isoplectron parallelum sp. nov. , paratype. Ahumairangi Town Belt, Wellington (NMNZ AI.071899). D–F . Praecantrix silvatica silvatica gen., sp. et subsp. nov. D . Paratype. Smoothwater Bay, South Westland (NMNZ AI.071901). E–F . Aspiring Hut, Mt Aspiring NP (MPN CW3518). G–I . Praecantrix silvatica lutea gen., sp. et subsp. nov. G . Paratype. Ōpoho, Dunedin (NMNZ AI.071903). H–I . McLean Falls, Catlins (MPN CW4946). J–L . Praecantrix saxicola gen.et sp. nov. , paratype. Mt St Bathans, Central Otago (NMNZ AI.071905). Scale bars: 1 mm. FEMALE TERMINALIA . Subgenital plate consists of two large, elongated lobes, flat at the vertex, which is covered in short hair ( Fig. 17G ). Ovipositor three quarters of body length, tapering and curving upwards gradually along its whole length. Lower valve of ovipositor with 6 teeth below at the apex. Dorsal surface of upper valve finely serrated in distal half ( Fig. 17H–I ). Distribution and habitat A cryptic, arboreal insect, confined to the north-west regions of New Zealand’s South Island between Lewis Pass and Kahurangi National Park ( Fig. 10E ). It is believed to live primarily in the tree canopy in native forests.