Maculinea alcon is a fairly rare resident. Between 1965 and 1990, the species distribution shrunk by 67%. Furthermore, the Dutch Monitoring Scheme shows a steep decline in numbers after 1997. The number of populations fell from 160 in 1990 to 90 in 2000. This continual decline is related to the deterioration of the habitat and the degree of isolation of the populations. Maculinea alcon is classified as 'endangered' on the 2006 Red List. It occurs on wet heathland and humid, nutrient-poor meadows with Gentiana pneumonanthe and one of the host ant species, Myrmica ruginodis or M. scabrinodis. It flies in one generation from early July until mid-August and hibernates in the nest of a host ant as a half-grown caterpillar.
Wynhoff, I., Swaay, C. van, Groenendijk, D., Bosveld, M., Bos, F.
- Bos, F., M. Bosveld, D. Groenendijk, C. van Swaay & I. Wynhoff 2006. De dagvlinders van Nederland, verspreiding en bescherming. Nederlandse Fauna 7. De Vlinderstichting, Wageningen en Nationaal Natuurhistorisch Museum Naturalis, European Invertebrate Survey, Nederland.