At present, Erynnis tages is an extremely rare resident that is found in very low numbers on only two, or perhaps three, calcareous grasslands in the south of the province of Limburg. The species usually has one generation a year although there is sometimes a partial second one. It flies from mid-May until mid-June, hibernating as a fully-grown caterpillar. The species is classified as 'critically endangered' on the 2006 Red List. In the past, this was a fairly common species both on calcareous and on nutrient-poor, sandy soils in the south, central and eastern parts of the country. The larval foodplant is normally Lotus corni-culatus. Many populations became extinct between 1920 and 1930; run-off from neighbouring agricultural land often resulted in eutrophication of nutrient-poor sites. The few remaining populations are isolated, and too small to be sustainable. New habitat is needed in the surroundings.
Wynhoff, I., Bosveld, M., Groenendijk, D., Swaay, C. van, 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.