Sigaus villosus


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 New Zealand. Like all of New Zealand sub-alpine and alpine grasshoppers Sigaus villosus has a 3 or 4 year 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. These flightless grasshoppers have distinctive black eyes.

Distribution and habitat

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 and as far north as the Mount Wilson. The black eye grasshopper is a truly high alpine species, as it prefers open bare rocky screes between in elevation. In the past, it could be found down as low as at the Porters Ski Area at the bottom of long open screes. With global warming Sigaus villosus is expected to lose between 20% and 95% of its distribution.

Species description

This species was first described by J. T. Salmon in 1950 and originally named Brachaspis villosa. The wings on S. villosus are micropterous between making this species flightless like most of New Zealand grasshoppers. Sigaus villosus is sister to the North Island alpine species Sigaus piliferus.

Polymorphism

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

Type information