Diachrysia chryson (Esper, 1789)

Host plants:
The larvae feed on Eupatorium cannabinum. In June 2014, I recorded a larva feeding on Salvia glutinosa that stood among Eupatorium.

Habitat:
Diachrysia chryson inhabits riparian forests, mountain forests, swamp woodlands and rather moist open forests with Eupatorium. It is mostly found in mountainous regions.

Life cycle:
The young caterpillar overwinters and is mature in May or June. They sit during the day on the underside of leaves, where they are well camouflaged. The moths fly mainly in July and August.

Endangerment: endangered

Endangerment factors:
Diachrysia chryson is endangered and clearly in decline by straightening of rivers and destruction of open moist forests (drainage, sinking water table, dense planting of non-native trees, afforestation of clearings, storage of logs, etc.).

Remarks:
The distribution ranges from Northern Spain through Central Europe (locally also in the south and north of Europe) to Japan.