Insects, one moment you curse them, the other you admire them. There is, however, no denying that they are both useful, and beautiful. And De Groote Heide is teeming with them. Certain areas are particularly rich in butterfly and dragonfly populations.
The Alcon blue is a special but vulnerable resident of De Groote Heide. The butterfly needs a special biotope in which to reproduce. The most important conditions are the presence of marsh gentian, a heather plant on which to lay their eggs, and certain ants. Some forest rangers have made it their mission to preserve the Alcon blue in the area.
The gatekeeper is – in contrast to the Alcon blue – a very common butterfly in the area.