Sigaus crassicauda

Sigaus crassicauda
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Orthoptera
Suborder:	Caelifera
Family:	Acrididae
Genus:	Sigaus
Species:	S. crassicauda
Binomial name
Sigaus crassicauda (Bigelow, 1967) [1]
The distribution of S. crassicauda in New Zealand

Sigaus crassicauda is a species of alpine grasshopper endemic to New Zealand.[2] Like all of New Zealand sub-alpine and alpine grasshoppers S. crassicauda has a 2 or 3 years life cycle. The eggs must ‘overwinter’ before they will hatch. Grasshoppers are found throughout the year and adult grasshoppers can be found throughout the New Zealand summer between December and April. Sigaus crassicauda cannot fly.

Distribution and habitat

Sigaus crassicauda among the flora of the Denniston Plateau

Sigaus crassicauda is only known from West Coast Region and Tasman Region of New Zealand.[3] It can be found as far south as the Right Branch of the Rahu River, Spring Junction (42°17′31″S 172°07′24″E) and as far north as the Thousand Acres Plateau, Matiri Range (41°35′37″S 172°19′21″E). Alpinacris crassicauda prefer alpine tussock grasslands between 1,200–1,500 metres (3,900–4,900 ft), however, can be found as low as 1,020 metres (3,350 ft) on the Thousand Acres Plateau, Matiri Range (41°35′37″S 172°19′21″E). Climate change is likely to reduce the suitable habitat that this species can occupy by 10 - 60% of its current range.[4]

Species description

The wings on S. tumidicauda are micropterous (small wings) between 2–4 millimetres (0.079–0.157 in) making this species flightless like most of New Zealand grasshoppers. Male body length 18–22 millimetres (0.71–0.87 in); Female body length 25–35 millimetres (0.98–1.38 in).

Sigaus crassicauda was described in 1967 by Robert Sidney Bigelow,[1] in the genus Alpinacris[5], with type locality of Lead Hills, Boulder Lake (40°53′35″S 172°32′56″E). A male holotype and paratype are deposited in the Canterbury Museum, Christchurch.

Type information

• Bigelow, R.S. 1967: The Grasshoppers of New Zealand, Their Taxonomy and Distribution. University of Canterbury, Christchurch.
• Type locality: Lead Hills, Boulder Lake, Tasman Region. 40°53′35″S 172°32′56″E
• Type specimen: Male; 27 October 1963; P. M. & M Johns. Holotype and Paratype are deposited in the Canterbury Museum, Christchurch.

References

1. R. S. Bigelow (1967). The Grasshoppers of New Zealand, their Taxonomy and Distribution. Christchurch: University of Canterbury.
2. Trewick, Steven A.; Koot, Emily M.; Morgan-Richards, Mary (2023). "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.
3. Morris SJ. 2002. Distribution and Taxonomic status of New Zealand endangered grasshoppers (Orthoptera: Acrididae). Department of Conservation, Wellington.
4. Koot, Emily M.; Morgan-Richards, Mary; Trewick, Steven A. (2022). "Climate change and alpine-adapted insects: modelling environmental envelopes of a grasshopper radiation". Royal Society Open Science. 9 (3). doi:10.1098/rsos.211596. ISSN 2054-5703. PMC 8889178. PMID 35316945.
5. "Orthoptera Species File - Sigaus Hutton, 1898". orthoptera.speciesfile.org. Retrieved 2024-09-10.