H. obvoluta is endangered within its whole distribution range. It is a C. European species, distributed from the Pyrennees and the Atlantic coast of France to southern Slovakia and northern Hungary; it occurs also in Great Britain, Schleswig-Holstein, southern part of Moravy, Albania, Bosnia, northern Serbia and in Italy. In Poland it has few localities in the central Sudetes. It is a typical forest-dweller of montane areas, associated with dead timber which is necessary for its reproduction, feeding and hibernation. Its presence in ten sites in Poland has been confirmed. The main threats for the species are clear-felling and removal of dead timber.