Six years from passing bell to recovery: Habitat restoration of the threatened Chequered Blue Butterfly (<i>Scolitantides orion</i>) in SE Finland

Abstract

We restored the habitat of the vulnerable Chequered Blue Butterfly (Scolitantides orion Pallas). The population at the restoration site almost became extinct in the late 1980's due to overgrowth by Scots pine forest. The habitat was restored by selective removal of pines in 1990. The abundance of S. orion was estimated in 1990-1996 and 1998-1999, and the population was studied intensively over a short period in 1997. The butterfly recovered after some delay. The numbers of specimens were low during the first five years, but a marked change in 1996- 1999 indicated the presence of a persistent population. The habitat restoration most likely prevented the local extinction of S. orion.