Mystes planatus (A False Darkling Beetle)

Family Melandryidae. This unusual, rather flattened beetle is unlike a typical members of its family, and is rare. The larva is exceedingly thin and stick-like, and presumably feeds in dead wood or woody fungi like others of its family.

http://www.bookofinsect.com/determination/mystes-planatus-382.html

Regional distribution

Mystes planatus is listed in the following regions: