The Dutch alcon blue (Phengaris alcon arenaria) was a subspecies of the alcon blue butterfly (Phengaris alcon). There is not much known about this subspecies, but it has always been very rare. It was endemic to the Netherlands, where two populations were known. One in Meijendel (dunes north of The Hague), and in the Meije (in the neighbourhood of the Nieuwkoopse Plassen). The population in the Meije disappeared in 1975 and in Meijendel this subspecies disappeared in 1979.