Spialia sertorius is a former resident. It disappeared in 1976. It mainly occurred on calcareous grasslands in the south of the province of Limburg, where it used Sanguisorba minor as larval foodplant. The species flew in one, sometimes two, generations, and hibernated as a fully-grown caterpillar. On the 2006 Red List, it is classified as 'extinct'. However, if additional habitat is developed in abandoned marl pits and the former habitat managed appropriately, butterflies from the neighbouring Belgian population may colonise the southern part of Limburg.
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.