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Volume 87, 1959
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Revision of the Rhaphidophoridae (Orthoptera) of New Zealand—Part VI.
A New Species Belonging to the Genus Pachyrhamma Brunner, 1888

[Received by the Editor, April 22, 1959.]

Abstract

A fresh key is given to the genus Pachyrhamma Brunner. A new species, Pachyrhamma longicauda n.sp., is described and illustrated. Attention is drawn to its close relationship with P. longipes (Colenso).

Introduction

Six specimens of a new species of Rhaphidophoridae belonging to the genus Pachyrhamma Brunner are described here. They are part of the insect collection of the Auckland Institute and Museum and unfortunately very little information is available about them, the date and name of collectors not being on the labels. Three labels have Taumarunui written in an unknown handwriting, one label has Ohakune written in the handwriting of Mr. C. E. Clarke, so it is assumed that he collected this specimen; the other two specimens are without labels. This species is very closely related to the tree-dwelling species, Pachyrhamma longipes (Colenso) and P. delli (Richards), with similar sturdy hind legs, in contrast to the attenuated slender legs of the cave-dwelling species in this genus.

As three further species have recently been added to the genus Pachyrhamma Brunner, bringing the total number of species known to eight, a fresh key to the genus is now necessary.

Key to the Species of Pachyrhamma
1. Antennae in male armed with spines 2
Antennae in male without spines 4
2. Antennae in male with numerous small, sharp spines P. fascifer (Walker)
Antennae in male with large or small blunt spines 3
3. Antennae in male with 5 or 6 large; blunt spines; posterior femora (male and female) bearing approximately 21 retrolateral and 12 prolateral linear spines beneath P. acanthocera Milligan
Antennae in male with approximately 9 small, blunt spines, posterior femora (male and female) bearing approximately 3 retrolateral and 8 prolateral linear spines beneath P. fusca Richards
4. Fore femur without linear spines P. waitomoensis Richards
Fore femur with linear spines 5
5. Posterior tibia with approximately 35 prolateral and 38 retrolateral linear spines above P. uncata Richards
Posterior tibiae with approximately less than 27 prolateral or retrolateral linear spines above 6
6. Hind tarsus without linear spines P. longipes (Colenso)
Hind tarsus with linear spines 7
7. Suranal plate in male and female without median spine P. longicauda n.sp.
Suranal plate with a small, blunt, median spine in female; and a large, blunt, median spine in male P. delli (Richards)
Genus Pachyrhamma. Brunner, 1888

Pachyrhamma longicauda n.sp. Text-fig. 1, figs. 1–6.

Colour. Basic colour light brown, with pronotum, mesonotum, metanotum and abdominal terga irregularly mottled with mid-brown and ochreous, femora and tibiae banded

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Transactions of the Royal Society of New Zealand Vol. 87, Parts 3 and 4, pp. 329–332, 1 Text-fig., November, 1959.

Picture icon

Text-fig. 1—Pachyrhamma longicauda n.sp. Fig. 1—Female genitalia, dorsal view. Fig. 2—Female genitalia, ventral view. Fig. 3—Female genitalia, ventral view showing variation in shape of subgenital plate. Fig. 4—Male genitalia, dorsal view. Fig. 5—Male genitalia, ventral view, subgenital plate in place. Fig. 6—Male genitalia, ventral view, subgenital plate removed to expose structures beneath.

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with light brown and ochreous, light brown at their junction; tibiae and tarsi ochreous at their junction; tarsi ochreous; antennae ochreous, ovipositor light reddish-brown.

Body. Length up to 24.5 mm. Dorsal surface of body sparsely clothed with setae; ventral surface sparsely clothed with setae. Ovipositor 0.8 as long as body. Antennae broken. Maxillary palps with third and fourth segments subequal in length. Pronotum margined anteriorly and laterally; mesonotum margined laterally. Bodies of male and female sub-equal.

Antennae. As in generic description. Third segment narrower than pedicel, on dorsal aspect 1.4 as long as pedicel in male and 1.6 as long as pedicel in female; on ventral aspect 1.1 as long as pedicel in male and 1.3 as long as pedicel in female. Sexual dimorphism well developed, male possessing longer, stouter antennae than female; no spines present on flagellum of male or female.

Legs. Long and slender. Fore and middle legs subequal in length, with hind leg twice length of fore and middle legs. Sexual dimorphism poorly developed, fore and middle legs of female being subequal in length with those of male; hind legs of female 0.85 as long as those of male. Femora, tibiae and two proximal segments of hind tarsi armed with variable number of linear spines (Table I). No spines occur on fore or middle tarsi. Apical spines constant in number, as in generic description. First segment of hind tarsus 0.8 length of other three together. Ratio of length of legs to length of body—Fore leg: male, 1.36:1; female, 1.26:1. Middle leg: male, 1.30:1; female, 1.28:1. Hind leg: male, 2.72·1; female, 2.49:1.

[The section below cannot be correctly rendered as it contains complex formatting. See the image of the page for a more accurate rendering.]

Table I.—Variability in Number of Linear Spines on the Legs of Six Specimens of Pachyrhamma Longicauda N. Sp.
Arith. Mean Std. Dev. Range
L. R. L. R. L. R.
Fore Femur Pro. 2.8 2.6 1.0 0.5 2–4 2–3
Inf. Retro. 0 0 0 0 0 0
Fore Tibia Pro. 2.8 3 0.4 0 2–3 3
Inf. Retro. 3 3 0 0 3 3
Fore Tarsus Pro. 0 0 0 0 0 0
Retro. 0 0 0 0 0 0
Mid. Femur Pro. 0.3 0.4 0.8 0.5 0–2 0–1
Inf. Retro. 1.5 1.4 0.8 0.5 0–2 1–2
Mid. Tibia Pro. 2.8 2.8 0.8 0.4 2–4 2–3
Sup. Retro. 3.0 2.8 0.6 0.4 2–4 2–3
Mid Tibia Pro. 3 3 0 0 0 0
Inf. Retro. 3 3 0 0 0 0
Mid Tarsus Pro. 0 0 0 0 0 0
Retro. 0 0 0 0 0 0
Hind Femur Pro. 7.5 7.5 0.6 0.8 7–8 6–8
Inf. Retro. 3.8 3.7 3.1 1.8 2–10 2–7
Hind Tibia Pro. 16.7 18.4 3.6 4.3 12–20 11–22
Sup. Retro. 21.0 22.6 4.3 3.6 15–26 17–26
Hind Tarsus Pro. 2.2 2.2 0.4 0.4 2–3 2–3
1 Sup. Retro. 2.3 2.4 0.8 0.9 2–4 2–4
Hind Tarsus Pro. 0.7 0.8 0.5 0.4 0–1 0–1
2 Sup. Retro 0.7 0.8 0.5 0.4 0–1 0–1

Genitalia. Female: Suranal plate, Fig. 1 (SAP), concave laterally, distal margin truncate; distolaterally the plate bears two groups of setae. Subgenital plate, Fig. 2 (SGP), straight laterally, tapering to a point distally; or Fig. 3, emarginate distally; plate sparsely clothed with setae. Male: Suranal plate, Fig. 4 (SPL), concave laterally, truncate distally; whole plate thickly coated with short setae. Subgenital plate (hypandrium), Fig. 5 (H), triangulate, 1.1 longer than wide, sides spreading slightly proximally, changing to concave medianly, attenuated distally with rounded apex. Apical protuberance on ventral surface

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thickly clothed with short setae. On dorsal surface more proximal portion of plate sparsely clothed with setae, more distal portion glabrous. Two styli, Fig. 5 (S), thickly clothed with short setae, length of styli being 0.33 length of sternite IX. Subgenital plate covers genitalia. Parameres, Figs. 5, 6 (P), attenuated, broad at base, prolateral margin thickly clothed with long setae, rest of paramere more sparsely clothed with short setae. Pseudosternite, Fig. 6 (PD), as long as broad, tapering to a rounded apex distally. Penis, Fig. 6 (PN), two-lobed, each lobe as broad as long. Paraprocts, Figs. 4, 5, 6 (PP), 0.7 as wide as long.

Locality. Taumarunui (type locality), coll. and date unknown; Ohakune, coll. C.E. Clarke, date unknown.

Types. Holotype male, allotype female, two paratype males and two paratype females in Auckland Institute and Museum Collection.

This species is very closely related to Pachyrhamma longipes (Colenso), but differs from it in:

1.

Presence of linear spines on hind tarsi.

2.

Sexual dimorphism in length of legs not as well developed as in P. longipes

3.

Fewer linear spines on hind femora.

4.

Greater number of linear spines on hind tibiae.

Acknowledgments

I wish to thank Dr. Gilbert Archey, Director of the Auckland Institute and Museum, for permission to examine the material discussed in this paper; and Dr. H. R. Thompson, of the Applied Mathematics Laboratory, for assistance in preparing the table.

Literature Cited

Colenso, W., 1887. A Description of a large and new species of Orthopterous Insect of the Genus Hemideina Walker. Trans. N.Z. Inst., 19:145–147.

Richards, Aola M., 1958. Revision of the Rhaphidophoridae (Orthoptera) of New Zealand. Part III. The Genera Pachyrhamma Brunner and Pallidoplectron Richards. Trans. Roy. Soc. N.Z., 85: 695–706.

Dr. Aola M. Richards

,
Plant Diseases Division,
Department of Scientific and Industrial Research,
Private Bag, Auckland, New Zealand

Index to Text-figure
  • B—basivalvula.

  • BC—basal segment of cercus.

  • C—cercus.

  • DE—ductus ejaculatorius.

  • DV—dorsal valve.

  • E—endapophysis.

  • EP—endoparamere.

  • FCA—feebly chitinised arch connecting rami.

  • H—subgenital plate, male.

  • IA—intersegmental apodeme.

  • MR—muscle attached to ramus.

  • MT IX—membrane of tergite IX.

  • P—paramere (ectoparamere).

  • P VII, P VIII, P IX—pleurite VII, VIII, IX.

  • PD—pseudosternite.

  • PM—perianal membrane.

  • PN—penis.

  • PP—paraproct.

  • S—stylus.

  • S VII, S VIII, S IX—sternite VII, VIII, IX.

  • SAP—supra-anal plate, female.

  • SGP—subgenital plate, female.

  • SPL—supra-anal plate, male.

  • T VII, T VIII, T IX, T X—tergite VII, VIII, IX, X.

  • 1 VF—first valvifer.

  • 2 VF—second valvifer.

  • VV—ventral valve.

Index to Table

  • Arith. mean—Arithmetic mean.

  • Inf.—Inferior.

  • Prol.—Prolateral.

  • Retro.—Retrolateral.

  • Std Dev.—Standard Deviation.

  • Sup.—Superior.

  • Mid.—Middle.

  • L.—Left leg.

  • R.—Right leg.