Sigaus

The genus Sigaus is endemic to New Zealand and with all but one species endemic to the South Island. Sigaus piliferus is currently the only representative of the endemic grasshopper genera found in the North Island. There are eight species within this genus[2][3]. All species are flightless and many have colouration to camouflage against rocky ground. Sigaus minutus and S. childi are threatened species[4].

Sigaus
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Orthoptera
Family:	Acrididae
Genus:	Sigaus Hutton, 1897[1]
Species
Sigaus australis Sigaus campestris Sigaus childi Sigaus homerensis Sigaus minutus Sigaus piliferus Sigaus obelisci Sigaus takahe Sigaus villosus

The genus Sigaus is distinguished from other genera within this family in New Zealand by the distinctive structures of the male genitalia. The epiphallus lophi are saddle-like in shape with the mesal protuberance of the lophus having a smooth, rounded outline. These structures are internal of the male genitalia.[5] However, the genus is not monphyletic with respect to other New Zealand grasshoppers.[6]

The taxonomy of New Zealand endemic grasshoppers was substantially revised by Bigelow in 1967.[2] This review was mostly based on the female genitalia.

	Sigaus australis	Sigaus campestris	Sigaus childi	Sigaus homerensis	Sigaus minutus	Sigaus piliferus	Sigaus obelisci	Sigaus takahe	Sigaus villosus
Photograph
Elevation[7]	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 (5,900-6,900 ft)
Described[8]	1897[1] Hutton	1897 Hutton	1999[9] Jamieson	2003[10] Morris	1967[11] Bigelow	1897 Hutton	1967 Bigelow	2003 Morris	1950[12] Salmon
Habitat[13]	Tussock grasslands	Dry rocky hillsides/ Tussock grasslands	Dry rocky hillsides	Tussock grasslands	Fluvial outwashs	Tussock grasslands	Alpine lichen fields	Tussock grasslands	Srcees
Polymorphism[14]	Highly crypsis	Highly crypsis	Highly crypsis	2	Highly crypsis		Highly crypsis		1
Regions	Canterbury Otago	Canterbury Otago Southland	Otago	Southland	Canterbury	Waikato Gisborne Hawke's Bay Manawatū-Whanganui Wellington	Otago	Southland	Canterbury
Size[15]	Medium	Medium/large	Medium	Medium	Very small	Large	Large	Medium	Large
Threaten[16]	Not threaten	Not threaten	Nationally Critical	Range Restricted	Nationally Endangered		Range Restricted	Range Restricted	Not threaten
Wings[17]	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. 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. 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.
5. 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.
6. 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.
7. Species prefer altitude.
8. The author and year the species was described.
9. A new species of Sigaus from Alexandra, New Zealand (Orthoptera: Acrididae). New Zealand Journal of Zoology, 26: 43-48.
10. 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
11. Bigelow, R.S. 1967: The Grasshoppers of New Zealand, Their Taxonomy and Distribution. University of Canterbury, Christchurch.
12. 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
13. Species prefer habitat.
14. The number of colour morphs known for adults of this species.
15. Size for adult males: Small less than 6 mm; Medium 6-30 mm & Large greater than 30 mm.
16. Base on the New Zealand Threat Classification System
17. Species wing length.

External links

• Radio New Zealand Critter of the Week Sigaus Grasshopper 3 March 2017
• Citizen science observations