Maria Karnebring, nature conservation officer at the farm Västtomta outside Söderköping, shows us into a lush forest area next to a dirt road.
- Here we will soon discover them. It used to be pasture here but now it's a mixture of oak and hazel, and so is the grass puffin, which they need to breed, she says.
And very true. It doesn't take many minutes for several butterflies to swirl around us. Rebecca Petersen, who works as an inventor for the county administrative board, is trying bravely to catch a butterfly in the net.
- It is very important to map where the endangered dolphin butterfly is, so we can make efforts there to preserve the species, she says.
The county administrative board has followed the weed butterfly since 1999 with recurring inventories over the years. Kenneth Claesson, biologist at the county administrative board, sees that the butterfly's habitats are threatened.
- Yes, we need to encourage landowners to make clearing efforts and maybe cut down some trees, in order to prevent old natural pastures from growing again. The best thing would be if you could have a low-intensity pasture on these fields, which is lagging behind, "says Kenneth Claesson.
In Östergötland you can find the weed grass butterfly south of Linköping, Åtvidaberg and around Söderköping.