Sigaus
Sigaus piliferus
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Orthoptera
Suborder: Caelifera
Family: Acrididae
Tribe: Catantopini
Genus: Sigaus
Hutton, 1897[1]
Species

Sigaus australis
Sigaus campestris
Sigaus childi
Sigaus homerensis
Sigaus minutus
Sigaus piliferus
Sigaus obelisci
Sigaus takahe
Sigaus villosus

Sigaus of grasshoppers in the tribe Catantopini that isendemic to New Zealand, and all but one species is endemic to the South Island: Sigaus piliferus is the only North Island representative and is the type species. There are eight species in the genus; all are flightless, and many are coloured for camouflage against rocky ground.[2][3] Sigaus minutus and S. childi are threatened with extinction.[4]

Taxonomy

The taxonomy of New Zealand endemic grasshoppers was substantially revised by Bigelow in 1967, based mostly on female genitalia,[2] and again in 2023 using genetic data.[5] The New Zealand radiation of cold-adapted grasshoppers is monophyletic but neither genetics nor morphology resolve distinctive genera, therefore it was suggested that all thirteen species be placed in the genus Sigaus.[5] The genus Sigaus is distinguished from other Acrididae as flightless, silent acridids with short tegmina, crypsis colouration and endemic to New Zealand. Each species has distinctive pronotum shape and structures of the internal male genitalia: the epiphallus lophi are saddle-like in shape with the mesal protuberance of the lophus having a smooth, rounded outline.[6] The genus is monophyletic and sister to grasshoppers from Tasmania, Australia.[7]

Sigaus australisSigaus campestrisSigaus childiSigaus homerensisSigaus minutusSigaus piliferusSigaus obelisciSigaus takaheSigaus villosus
Photograph
Elevation[8]1,300–1,700 m
(4,300–5,600 ft)
400–1,500 m
(1,300–4,900 ft)
200–500 m
(660–1,600 ft)
900–1,000 m
(3,000–3,300 ft)
300–800 m
(980–2,600 ft)
1,600–1,800 m
(5,200–5,900 ft)
1,000–1,400 m
(5,900–6,900 ft)
1,800–2,100 m
(–6,900 ft)
Described[9]1897[1]
Hutton
1897
Hutton
1999[10]
Jamieson
2003[11]
Morris
1967[12]
Bigelow
1897
Hutton
1967
Bigelow
2003
Morris
1950[13]
Salmon
Habitat[14]Tussock grasslandsDry rocky hillsides/
tussock grasslands
Dry rocky hillsidesTussock grasslandsFluvial outwashTussock grasslandsAlpine lichen fieldsTussock grasslandsScree
Polymorphism[15]Highly crypticHighly crypticHighly cryptic2Highly cryptic2 Highly cryptic1
RegionsCanterbury
Otago
Canterbury
Otago
Southland
OtagoSouthlandCanterburyWaikato
Gisborne
Hawke's Bay
Manawatū-Whanganui
Wellington
OtagoSouthlandCanterbury
Size[16]MediumMedium/largeMediumMediumVery smallLargeLargeMediumLarge
Status[17]Not threatenedNot threatenedNationally CriticalRange RestrictedNationally EndangeredNot threatenedRange RestrictedRange RestrictedNot threatened
Wings[18]Micropterous
2–3 mm
Micropterous
2–3 mm
Micropterous
1–2 mm
Micropterous
2–3 mm
Micropterous
1 mm
Micropterous
3–4 mm
Micropterous
3–4 mm
Micropterous
2–4 mm

References

  1. 1 2 Hutton, F.W. 1897: "The grasshoppers and locusts of New Zealand and the Kermadec Islands". Transactions of the New Zealand Institute 30: 135-50
  2. 1 2 Bigelow, R.S. 1967. The Grasshoppers of New Zealand, Their Taxonomy and Distribution. University of Canterbury, Christchurch. p. 60.
  3. Jamieson, Colleen D. (1999). "A new species of Sigaus from Alexandra, New Zealand (Orthoptera: Acrididae)". New Zealand Journal of Zoology. 26 (1): 43–48. doi:10.1080/03014223.1999.9518176. ISSN 0301-4223.
  4. Trewick, S. A.; Morris, S. J.; Johns, P. M.; Hitchmough, R. A.; Stringer, I. A.N. (2012). "The conservation status of New Zealand Orthoptera". New Zealand Entomologist. 35 (2): 131–136. doi:10.1080/00779962.2012.686318. ISSN 0077-9962. S2CID 219564547.
  5. 1 2 Trewick, Steven A.; Koot, Emily M.; Morgan-Richards, Mary (2023-12-11). "Māwhitiwhiti Aotearoa: Phylogeny and synonymy of the silent alpine grasshopper radiation of New Zealand (Orthoptera: Acrididae)". Zootaxa. 5383 (2): 225–241. doi:10.11646/zootaxa.5383.2.7. ISSN 1175-5334.
  6. Morris, S.J. 2002: Identification guide to grasshoppers (Orthoptera: Acrididae) in Central Otago and Mackenzie Country. DOC Science Internal Series 26. Department of Conservation, Wellington. 17 p.
  7. Koot, Emily M.; Morgan-Richards, Mary; Trewick, Steven A. (2020). "An alpine grasshopper radiation older than the mountains, on Kā Tiritiri o te Moana (Southern Alps) of Aotearoa (New Zealand)". Molecular Phylogenetics and Evolution. 147: 106783. doi:10.1016/j.ympev.2020.106783. ISSN 1055-7903. PMID 32135305. S2CID 212567788.
  8. Species prefer altitude.
  9. The author and year the species was described.
  10. A new species of Sigaus from Alexandra, New Zealand (Orthoptera: Acrididae). New Zealand Journal of Zoology, 26: 43-48.
  11. Morris, S.J. 2003: "Two new species of Sigaus from Fiordland, New Zealand (Orthoptera: Acrididae)". New Zealand entomologist, 26: 65–74. PDF Archived 2011-07-21 at the Wayback Machine
  12. Bigelow, R.S. 1967: The Grasshoppers of New Zealand, Their Taxonomy and Distribution. University of Canterbury, Christchurch.
  13. Salmon, J.T. 1950: A new species of Acrididae (Insecta: Orthoptera) from New Zealand. Transactions of the Royal Society of New Zealand, Vol. 78, Part 1, page 69, February 1950
  14. Species prefer habitat.
  15. The number of colour morphs known for adults of this species.
  16. Size for adult males: Small less than 6 mm; Medium 6-30 mm & Large greater than 30 mm.
  17. Base on the New Zealand Threat Classification System
  18. Species wing length.
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