Lythria purpuraria (Linnaeus, 1758)

Host plants:
The caterpillars live on Polygonum aviculare (knotweed).

Habitat:
Lythria purpuraria loves fairly warm temperatures and inhabits sandy grasslands, dry dirt road edges, extensive pastures and dry or alternating dry cropland and gappy grassland with the occurrence of the larval host plant. In Northern Greece I found Lythria purpuraria quite common on the west side of Mount Olympus in extensive fields and meadows with Lycaena thersamon and in the Askio mountains in ruderal terrain in the fields.

Life cycle:
The moths fly from late April to September in two or three generations (north of the Alps, usually two, from May to June and in July/August). The caterpillars live from May to October. The pupa overwinters.

Endangerment: strongly endangered

Endangerment factors:
Lythria purpuraria is threatened with extinction north of the Alps due to the decline in sandy grasslands and extensive dry fields. In southern Europe however, Lythria purpuraria is even less at risk.

Remarks:
Lythria purpuraria is widespread in Southern and Central Europe and temperate Asia to Western China.