Despite some positive reports of growing numbers of butterflies in the Netherlands, the overall situation still gives rise for concern. There are species which are declining rapidly and others have even already disappeared. Habitat destruction and extreme weather conditions in 1986/1987 have caused the Pearly Heath (Coenonympha arcania) to be come extinct. There have been no sightings of the butterfly since 1988. There is also bad news regarding the Small Pearl-bordered Fritillary (Clossiana selene) and the Large Chequered Skipper (Heteropterus morpheus). Colonies of these rare species have now disappeared from sites which were stongholds until recently. The reason for the sudden decline and regional disappearance of these two butterfly species is not known.