Silvanus bidentatus Fabricius was assessed as RDB Rare in the British Red Data Book (Shirt, 1987) but down-graded to 'Notable B' by Hyman (1992), but should it have had any conservation status at all? Allen (1956) pointed out that the first three localities - near Manchester, Newcastle and Paisley - are all in the vicinity of large ports or industrial areas and widely separated. It was subsequently discovered in the London area, and began to turn up in previously well-worked areas of the South East of England. He wondered if this signified that the beetle was originally introduced in shipping or merchandise but quickly established itself and has continued to expand its British range. This does seem prophetic given its current continued expansion.
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