24 January 2013

Darkling Beetle - Hypaulax orcus

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Darkling Beetle - Hypaulax orcus 

This black beetle has a distinctive embossed pattern on its hardened forewings (elytra), but is poorly recorded, there being only a few collections and these mainly from northern Victoria and SA, with two from WA. One of these is from Geraldton and the other Kellerberrin (east of Perth) (Australian Faunal Directory). Despite this poor record, they seem to be quite common in dry mallee country (around 140 km or 90 miles) to the NE and NW of Esperance, where observed on dead woody matter. 

Habitat foundation is highly variable and includes gravel, sand and granite, the essential ingredient being fallen (dead and decaying) timber. Hypaulax orcus is a largish slow moving beetle (commonly playing dead) that grows to around 2.5 cm (1”) in length and like many Darkling Beetles is not anti-social, evidenced by several individuals found feeding together on the same piece of slowly decaying material. 

The Hypaulax genus is a member of the large Tenebrionidae (Darkling Beetle) family. 

My thanks to Kim Pullen of the Australian National Insect Collection, CSIRO Ecosystem Sciences who very kindly identified this species.