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.
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 (-43.8389°N 170.7839°W) and as far north as the Mount Wilson (-42.9588°N 171.6756°W). The black eye grasshopper is a truly high alpine species, as it prefer open bare rocky screes between 1900m-2100mm (6,200feet-6,900feetm) in altitude,[1] [2] however, it can be found down as low as 1320m (4,330feet) at the Porters Ski Area at the bottom of long open screes (-43.273°N 171.6422°W). Adult grasshoppers are found during the New Zealand summer between October and March.
This species was first described by J. T. Salmon in 1950 and originally named Brachaspis villosa.[3] The wings on S. villosus are micropterous (small wings) between 2mm4mm making this species flightless like most of New Zealand grasshoppers.
Only one colour morph are known for adults S. villosus, 'Grey'. All specimens are light grey with black coloured eyes.