The caterpillar feeds on grasses (Cyperaceae and Poaceae), especially on Carex alba, Carex brizoides and Brachypodium.
Lopinga achine needs clear, open forests which are rich in undergrowth and grasses (Carex!) and show a larger age diversity. For example, it flies in the coppice woodlands or in floodplain forests along rivers. Clear and moist spruce forests are also colonized, while dense, low-light spruce forests provide no habitat.
The caterpillar overwinters as L3. I found caterpillars in early May in the evening at Carex alba near Memmingen (Southern Germany). Pupation usually takes place in late May or early June in the ground vegetation or small shrubs and tree bases. The adults fly in June and July. The peak of the males is usually between 15 and 25 June at about 600m above sea level, the peak of the females between 22 June and early July.
The males like to play around individual shrubs or trees that bear branches down to the ground. Sometimes several males suck water together on open soil on untarred forest roads.
Females live quite withdrawn. At Memmingen they sat in the grass preferably in semi-shady areas with old trees, where the ground was covere by a dense, but rather short growing carpet of grasses as Brachypodium sylvaticum and particularly Carex alba. Here they let occasionally fall single eggs with only slightly arched abdomen (no adhesive secretion).
Flowers are visited only occasionally and apparently mostly by females. The privet (Ligustrum vulgare) often plays a more important role.
Endangerment: threatened with extinction
Lopinga achine is threatened with extinction because of the darkening processes in the forests due to the increasing high forest management without (in this case, small to medium size) clearcuts, abandonment of old practices like coppice woodland or forest grazing, dense afforestation of the last clearing and fragmentation of forests (roads etc.).
Near Memmingen (Southern Germany) Lopinga achine occurred in higher abundances in the 1990s, but around the turn of the millennium there was a sharp decline (from 2009 somewhat recovered thanks to some lighter areas) because dense planting of spruce and maple, and beech occurs ebven today in the floodplains and because due to lowering of ground water levels and eutrophication from air overgrowing, compaction and shadowing increase, the grassy clearings almost have vanished and old, richly structured stocks with important reproduction habitats are sawn (bark beetles, blowdown, greed).
In addition, a part of the habitats have already been overgrown by an invasion of alien plants (Solidago, etc.) for example in the Upper Rhine Valley, which limits the habitat further.
An enforcement of nature preservation by law will still often be hopeless in (private) forests and thus a farce in many regions. On the other hand especially public forests are managed since long times usually in a way that there are no possibilities for survival any more.
Lopinga achine could in principle easily be helped with a marked thinning of stocks that have become too tight. Usually this is quickly resulting in higher abundances if executed carefully.
Lopinga achine occurs locally from France across central and Eastern Europe to northern Asia and Japan.