Praecantrix saxicola Hegg & Morgan-Richards & Trewick 2024, gen. et sp. nov.
Creators: name: Hegg, Danilo
name: Morgan-Richards, Mary
name: Trewick, Steven A.
Publisher: name: Zenodo
Year: 2024
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Orthoptera
Rhaphidophoridae
Praecantrix
Praecantrix saxicola

description: Praecantrix saxicola gen. et sp. nov.
urn:lsid:zoobank.org:act: 7888A528-5ABC-4CBA-AA33-4641DAA7CB26
Figs 3, 9, 10J, 12L, 13K, 16J–L, 19J–L, 23D
Diagnosis
The largest of the two species in the genus Praecantrix gen. nov. (body length 9 to 14 mm), it is characterised by sexual dimorphism, the females being larger than males, a pale grey colour throughout and a dense tomentum covering the whole insect. This is in contrast to Praecantrix silvatica gen. et sp. nov., which is glabrous and shiny, and has a clear, crisp line delimiting the white body under-parts from the dark dorsal regions.
In the western part of its distribution range, P. saxicola gen. et sp. nov. is sympatric with species of Pharmacus and with Notoplectron brewsterense. It is most easily differentiated from Pharmacus by its lighter coloration, smaller size and micro-habitat preferences, with Pharmacus being more often found in cracks in solid rock. Notoplectron brewsterense is stockier, with shorter legs, has articulated linear spines on the hind tibiae and is glabrous, whereas P. saxicola is covered in fine tomentum. Additionally, female Pharmacus and Notoplectron have a smooth upper valve of the ovipositor, whereas P. saxicola has an ovipositor serrated above in the distal third (Fig. 19K–L).
In Otago, P. saxicola gen. et sp. nov. is sympatric with Isoplectron pallidum. The latter species, however, prefers cracks or small pockets in solid rock, and (in spite of the name) has a darker body colour.
Etymology
The Latin noun ‘ saxum ’ means ‘stone’, ‘rock’; in the plural also ‘stony place’. The insect is a dweller of stony places.
Material examined (see also Supp. file 1: Table S12)
Holotype NEW ZEALAND • ♂, adult; Mackenzie (MK), Mt Wakefield, Aoraki / Mt Cook NP; 43.71987° S, 170.12763° E; 1450 m a.s.l.; 13 May 2017; D. Hegg leg.; broken rocks on ridgeline; night search + insect net; NMNZ AI.071904.
Paratype NEW ZEALAND • 1 ♀, adult; Central Otago (CO), Mt St. Bathans; 44.71826° S, 169.77104° E; 1650 m a.s.l.; 9 Mar. 2019; D. Hegg leg.; on rock bluffs; night search + insect net; GenBank: PP155085; NMNZ AI.071905.
Other material
NEW ZEALAND – Central Otago (CO) • 1 ♂, 1 ♀; Mt Kyeburn, Danseys Pass; 44.95471° S, 170.30851° E; 1100 m a.s.l.; Dec. 2013; T. Jewell leg.; in scree among bluffs; GenBank: PP155088, PP155089; MPN CW2574, CW2575 • 3 ♂♂; same data as for preceding; MPN CW2572, CW2573, CW2576 • 1 ♀; same data as for preceding; 16 Jan. 2017; D. Hegg leg.; night search + insect net; GenBank: PP155087; MPN CW3520 • 1 ♀; Awakino Ski-field, St Marys Range; 44.78° S, 170.31° E; 1800 m a.s.l.; 20 Apr. 1998; B. Sinclair leg.; in scree; MPN CW173 • 1 ♂; same data as for paratype; GenBank: PP155086; MPN CW4317 • 2 ♀♀; same data as for paratype; MPN CW4551, CW4552 • 3 nymphs; same data as for paratype; MPN CW4318 to CW4320. – Mackenzie (MK) • 1 ♂; Ahuriri River East Branch; 44.27917° S, 169.74279° E; 1720 m a.s.l.; 30 Apr. 2022; D. Hegg leg.; in scree among bluffs; night search + insect net; MPN CW5611 • 1 ♀; same data as for preceding; MPN CW5612 • 1 ♀; Mt Wakefield, Aoraki / Mt Cook NP; 43.70548° S, 170.12192° E; 1680 m a.s.l.; 12 Mar. 2016; D. Hegg leg.; on sparsely vegetated ground; night search; GenBank: PP155084; MPN CW2880 • 1 ♂; Mt Wakefield, Aoraki / Mt Cook NP; 43.71063° S, 170.12445° E; 1750 m a.s.l.; 18 Mar. 2017; D. Hegg leg.; broken rocks on ridgeline; night search + insect net; MPN CW3540 • 1 nymph; same data as for preceding; MPN CW3332 • 1 ♀; same data as for preceding; 17 Apr. 2017; MPN CW3946 • 1 nymph; same data as for preceding; MPN CW3947 • 1 ♀; Mt Wakefield, Aoraki / Mt Cook NP; 43.71798° S, 170.12875° E; 1540 m a.s.l.; 13 May 2017; D. Hegg leg.; broken rocks on ridgeline; night search + insect net; MPN CW3517. – South Canterbury (SC) • 1 ♂; Fox Peak; 43.84° S, 170.79 °E; 2000 m a.s.l.; 22 Feb. 2015; S. Trewick leg.; GenBank: PP155082; MPN CW2811 • 1 ♀; same data as for preceding; GenBank: PP155083; MPN CW2812.
Description
MEASUREMENTS. See Table 1. Sexual dimorphism in body length, with females being nearly 25% larger than males.
HEAD. Vertex pale with four brown lines running from the fastigium to the anterior margin of the pronotum, two above the eyes and two near the centre. Grey patches behind the eyes. Eyes grey-green. Frons, clypeus and labrum pale, with two faint dark patches below the scapes of the antennae. Labial and maxillary palps pale. Scapes and pedicels pale; flagellum reddish-brown.
THORAX. Pronotum, mesonotum and metanotum grey with a pale median line, covered in fine tomentum (Fig. 12L).
LEGS. Sexual dimorphism present. The hind tibiae are about the same length as the body in females, 10% longer than the body in males. Since females are larger than males by approx. 25%, females have longer legs. 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 up to one prolateral and one to three retrolateral ventral linear spines, the retrolateral ones being larger. Fore and mid tibiae armed with two pairs of ventral linear spines, one pair of ventral apical spines and one pair of dorsal apical spines. Hind tibiae armed with about 26 dorsal linear spines (min 22, max 33) on both the anterior and the posterior edge. 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 largest. First hind tarsal segment armed with two to seven dorsal linear spines; second hind tarsal segment occasionally armed with one dorsal linear spine.
ABDOMEN. All tergites covered in fine tomentum; grey with a pale median line running along the whole length of the body (Fig. 12L). Sternites pale.
MALE TERMINALIA. Same as in Praecantrix silvatica gen. et sp. nov., but with longer bristles on the two lobes at the apex of the subgenital plate (Fig. 16J–L). Cerci on average 15% of body length, covered in sparse, mostly short hair; conical in the basal half, tapering to a blunt tip in the distal half. Styli short and stumpy.
FEMALE TERMINALIA. Subgenital plate square, with two rounded lobes on the distal corners, not as pronounced as in Praecantrix silvatica gen. et sp. nov., covered with sparse hair at the apex (Fig. 19J). Ovipositor approximately 70% of body length; nearly straight and only weakly recurved upwards near the apex; lower valve with 5 to 7 teeth below at the apex; dorsal surface of upper valve finely serrated in distal third (Fig. 19K–L).
Distribution and habitat
A small alpine rhaphidophorid that inhabits the dry alpine regions east of the Southern Alps, in Central Otago and in the Mackenzie Country (Fig. 10J). It is predominantly found on scree slopes or boulder fields and is most easily recognised by the light grey or grey-brown body colour and grey-green eye colour. When disturbed, it jumps erratically up and down until it falls into a hole between rocks.
description: Published as part of Hegg, Danilo, Morgan-Richards, Mary & Trewick, Steven A., 2024, 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, pp. 1-75 in European Journal of Taxonomy 971 on pages 61-63, DOI: 10.5852/ejt.2024.971.2761, http://zenodo.org/record/14451786