Isoplectron armatum aciculatum Karny, 1937

Figs 3, 5, 8, 10A, 12B, 13B, 14D–F, 17D–F, 21D

Isoplectron aciculatum Karny, 1937: 230 .

Isoplectron calcaratum – Hutton 1896: pl. XIII fig. 19a.

Diagnosis

Morphologically very similar to Isoplectron armatum armatum, it can only be differentiated from the latter by examination of the adult male terminalia or by DNA analysis. Other minor differences between the two subspecies are a larger body size and longer legs in I. a. aciculatum (see Table 1), and frequently (but not always) an additional spine on both the prolateral and retrolateral inferior edges of the hind femur in the northern subspecies. The two subspecies, however, are allopatric, I. a. aciculatum being confined to the southern regions of New Zealand’s North Island, between Wellington, Tongariro and Gisborne, whereas I. a. armatum is only found in South Island.

Isoplectron armatum aciculatum could be confused with several species in the genus Neonetus; it is most easily differentiated from these by the slender, elongated shape of the hind femora, which are armed with a prominent spine underneath, and by the absence of a prolateral spine at the apex of the fore and mid femora.

Etymology

The Latin word ‛ăcĭcŭla ’ translates as ‘hair pin’. Named after the shape of the conspicuous spine on the retrolateral inferior edge of the hind femur in adult males.

Material examined (see also Supp. file 1: Table S2)

Holotype NEW ZEALAND • ♂, adult; Wellington (WN), Wellington; 41.3° S, 174.8° E; 1903 or earlier; G.V. Hudson leg.; OUMNH ENT-ORTH097.

Representative female

NEW ZEALAND • ♀, adult; Hawke’s Bay (HB), Mohi Bush Reserve; 39.85485° S, 176.89542° E; 450 m a.s.l.; 10 May 2023; D. Hegg leg.; on tree trunk in native forest; night search + insect net; NMNZ AI.071888 .

Other material

NEW ZEALAND – Wellington (WN) • 1 ♂ subadult, paratype of I. calcaratum; Wellington; 41.3° S, 174.8° E; 1896 or earlier; F.W. Hutton leg.; CMNZ 2021.17.7 • 1 ♀; Ahumairangi Town Belt, Wellington; 41.26896° S, 174.76929° E; 250 m a.s.l.; 9 Apr. 2022; D. Hegg leg.; in Veronica shrub; night search + insect net; MPN CW5606 • 1 ♀; Queen Elizabeth II Park, Paekākāriki; 40.96758° S, 174.97745° E; 40 m a.s.l.; 10 Jul. 2016; J. Nisbet leg.; in wētā motel on tree trunk; Genbank: PP155156; MPN CW3033 • 1 ♂; same data as for preceding; MPN CW3034 • 2 ♀♀; same data as for preceding; MPN CW3029, CW3030 • 2 nymphs; same data as for preceding; MPN CW3031, CW3032 • 1 ♂; Turitea Road, Palmerston North; 40.41496° S, 175.66401° E; 120 m a.s.l.; 28 Aug. 2004; S. Trewick leg.; on the ground; casual find; MPN CW139 • 1 ♂; same data as for preceding; 3 Apr. 2016; S. Trewick and M. Morgan-Richards leg.; in wētā motel on tree trunk; GenBank: PP155155; MPN CW2869 • 1 ♂; same data as for preceding; MPN CW2868 • 1 ♂; same data as for preceding; 19 Mar. 2017; GenBank: PP155154; MPN CW4625 • 1 ♀; same data as for preceding; GenBank: PP155162; MPN CW4624. – Wairarapa (WA) • 1 ♀; Bideford; 40.86653° S, 175.86795° E; 150 m a.s.l.; 18 Sep. 2004; S. Trewick and M. Morgan-Richards leg.; on rotting log; GenBank: PP155159; MPN CW156 • 1 ♂; same data as for preceding; MPN CW154 • 1 ♀; same data as for preceding; MPN CW155. – Rangitikei (RI) • 1 ♀; Big Hill Stream Track, Ruahine Range; 39.58789° S, 176.33173° E; 500 m a.s.l.; 2011; M. Lusk leg.; MPN CW1634. – Hawke’s Bay (HB) • 1 ♂; Cape Sanctuary, Cape Kidnappers; 39.66073° S, 177.04288° E; 160 m a.s.l.; 14 Mar. 2011; M. Lusk leg.; in rifleman nest box; GenBank: PP155161; MPN CW1626 • 1 ♂; same data as for preceding; 16 May 2011; M. Lusk leg.; under kānuka bark; GenBank: PP155158; MPN CW1635 • 1 ♂; same data as for preceding; 14 Jun. 2011; GenBank: PP155157; MPN CW1961 • 2 ♀♀; same data as for preceding; Sep. 2011; MPN CW1809A, CW1809B • 1 ♂; Kuripapango Track, Kaweka Range; 39.380° S, 176.334° E; 500 m a.s.l.; 27 Feb. 2012; M. Lusk leg.; MPN CW1884 • 1 ♀; Lorenbrey, Kahurānaki Rd; 39.8200° S, 176.8465 °E; 160 m a.s.l.; Sep. 2011; M. Lusk leg.; MPN CW2075 • 1 ♂; Ngaruroro River terrace; 39.36934° S, 176.32052° E; 520 m a.s.l.; 11 Mar. 2014; M. Lusk leg.; in mānuka /kānuka forest; GenBank: PP155160; MPN CW2657. – Gisborne (GB) • 1 ♂; Okitu Bush Scenic Reserve; 38.66506° S, 178.09982° E; 50 m a.s.l.; 9 Mar. 2023; R. Kleinpaste leg.; photograph only; iNaturalist 150680236. – Taupō (TO) • 1 ♀; Marshalls Road, Ohakune; 39.39469° S, 175.39605° E; 580 m a.s.l.; 5 Apr. 2023; D. Hegg leg.; on tree trunk on road side; night search + insect net; MPN CW5644 • 1 gynandromorph; same data as for preceding; 7 May 2023; GenBank: PP155165; MPN CW5645 • 1 ♂; same data as for holotype; 12–14 May 2023; in wētā motel; GenBank: PP155167; MPN CW5647 • 1 ♀; same data as for preceding; GenBank: PP155166; MPN CW5648 • 1 ♀; same data as for preceding; GenBank: PP155168; MPN CW5649 • 1 ♀; same data as for preceding; GenBank: PP155164; MPN CW5650 • 1 ♂; Marshalls Road, Ohakune; 39.39518° S, 175.39726° E; 580 m a.s.l.; 13 May 2023; D. Hegg leg.; on tree trunk on road side; night search + insect net; GenBank: PP155163; MPN CW5646 .

Description

MEASUREMENTS. See Table 1. No sexual dimorphism in body length.

HEAD. Same as in Isoplectron a. armatum .

THORAX. Same as in Isoplectron a. armatum (Fig. 12B).

LEGS. Same as in Isoplectron a. armatum, only longer (see Table 1). Hind femora most frequently armed with three retrolateral ventral linear spines; one of these very conspicuous, weakly curved. This spine is present in both males and females, but is much larger and more pronounced in males. Two prolateral ventral linear spines are generally also present but are much smaller.

ABDOMEN. Mottled dark brown, with pale dorsal spots on the sides of the first tergite (Figs 12B, 21D). Colour morphs with a pale diamond on the back or a pale longitudinal band are also commonly encountered.

MALE TERMINALIA. Subgenital plate similar to that in Isoplectron a. armatum, but glabrous at apex, and with a much wider keel (Fig. 14E); also shallower and not as strongly folded upwards at the edges, meaning that from the sides one can see through the gap between the subgenital plate and the paraprocts (Fig. 14F). Cerci 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, reaching to the apex of the subgenital plate. Paraprocts covered in dense, stout spinules at the apex; short but wide and protruding beyond the perimeter of the subgenital plate on the sides (Fig. 14D), visible from below (Fig. 14E).

FEMALE TERMINALIA. Subgenital plate consists of two small, rounded, asymmetrical lobes, covered by sparse hair at the apex; the two lobes separated by a small gap and not touching at the vertex (Figs 17D). Ovipositor same as in Isoplectron a. armatum (Fig. 17E–F).