Razor grinder

Appearance

The razor grinder is a large cicada with a forewing measuring 50–55 mm . Males and females are similar in color and markings. The head and thorax is red-brown with black markings. The wings are transparent with some brown discoloration.

The male's call lasts for a few seconds, increases in volume, suddenly stops, and then suddenly starts again. They usually silently feed throughout the afternoon, and then groups call at maximum volume around dusk. There is a secondary population, referred to as the laughing razor grinder, which is only observed in rainforest and wet sclerophyll forest, and has a distinct call.

Razor grinders can also emit a distress call – a fragmented irregular noise – upon being seized by a predator.

Distribution

The razor grinder is found along the east coast of Australia from Gladstone in Central Queensland south to Narooma in southern New South Wales, generally below 500 m elevation. It reaches inland to Toowoomba, Inverell, Tamworth and the Capertee Valley. It is common in Brisbane, but uncommon in Sydney. There is also an isolated population in Cathu State Forest. Their habitat is dry or wet sclerophyll forest or rainforest margins. They are most visible in December and January, sometimes appearing in early November in some years.

Behavior

Male razor grinders sing in large groups on the main trunks of tall eucalypts, especially spotted gum . In some years their numbers can be locally immense, but in other years very few adults emerge.

Adult razor grinders are wary and flighty, especially at dusk, and are difficult to approach. They are fast flyers.

Habitat

The razor grinder is found along the east coast of Australia from Gladstone in Central Queensland south to Narooma in southern New South Wales, generally below 500 m elevation. It reaches inland to Toowoomba, Inverell, Tamworth and the Capertee Valley. It is common in Brisbane, but uncommon in Sydney. There is also an isolated population in Cathu State Forest. Their habitat is dry or wet sclerophyll forest or rainforest margins. They are most visible in December and January, sometimes appearing in early November in some years.