Sigaus villosus

Black Eye grasshopper
A female Sigaus villosus
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Orthoptera
Family:	Acrididae
Genus:	Sigaus Hutton, 1898[1]
Species:	S. villosus
Binomial name
Sigaus villosus (Salmon, 1950)
The distribution of S. villosus in New Zealand

Sigaus villosus is New Zealand's largest grasshopper. It is only found in the central mountains of the South Island. The genus Sigaus is endemic to the New Zealand. Like all of New Zealand sub-alpine and alpine grasshoppers S. villosus has a 2 or 3 years life cycle. The eggs must ‘overwinter’ before they will hatch. Hoppers are found throughout the year and adult grasshoppers can be found throughout the New Zealand summer between December and April. Adult S. villosus do not overwinter.

Distribution and habitat

A overview of the S. villosus habitat.
Lagoon Peak 43°22′29″S 171°14′16″E / 43.374819°S 171.237881°E / -43.374819; 171.237881

Sigaus villosus is known from the central mountains of the South Island, with the largest population on the Craigieburn Range. It can be found as far south as the Fox Peak (43°50′20″S 170°47′02″E / 43.838913°S 170.78388°E / -43.838913; 170.78388) and as far north as the Mount Wilson (42°57′32″S 171°40′32″E / 42.958791°S 171.675611°E / -42.958791; 171.675611). The black eye grasshopper is a truly high alpine species, as it prefer open bare rocky screes between 1,900–2,100 metres (6,200–6,900 ft) in altitude, however, it can be found down as low as 1,320 metres (4,330 ft) at the Porters Ski Area at the bottom of long open screes (43°16′23″S 171°38′32″E / 43.27295483°S 171.64224886°E / -43.27295483; 171.64224886). Adult grasshoppers are found during the New Zealand summer between October and March.

Species description

The wings on S. villosus are micropterous (small wings) between 2–4 millimetres (0.079–0.157 in) making this species flightless like most of New Zealand grasshoppers.

Polymorphism

Only one colour morph are known for adults S. villosus, 'Grey'. All specimens are light grey with black coloured eyes.

Type information

• 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
• Type locality: Mount Torlesse, 1,524–1,707 metres (5,000–5,600 ft), Canterbury. 43°15′21″S 171°49′17″E / 43.255873°S 171.821448°E / -43.255873; 171.821448
• Type specimen: Immature female; J. T. Salmon; Holotype, Paratype and Allotype are deposited in the Museum of New Zealand Te Papa Tongarewa. Plesiotype are deposited in the Canterbury Museum, Christchurch.

References