Het voorkomen van de kleinvlekkige en grootvlekkige vorm van de Noordse glazenmaker (Aeshna subarctica) in Nederland

Aeshna subarctica elisabethae occurs in two colour morphs, forma interlineata and the typical morph. We describe the taxonomic history, summarise the identification features, and discuss the abundance of the two morphs in Europe and The Netherlands. In Europe, the typical form is the most abundant morph in mountainous areas. Records from The Netherlands show that the form interlineata is most common (34 of 38 records) and the typical form is very rare (4 of 38 records). The scarce literature suggests that genetic variation underlies colour polymorphism in this species. Natural selection may favour the typical form in colder years or areas and the form interlineata in warmer years, causing both temporal and geographical variation in the relative abundance of the two morphs.