Host plants:
The caterpillar lives on St. Johns wort species (Hypericum), particularly Hypericum perforatum.
Habitat:
Aplocera praeformata inhabits montane to subalpine grasslands, pastures, forests clearcuttings and forest edges.
Life cycle:
Aplocera praeformata flies in a single generation from June to early September. The caterpillar overwinters. I found them in the autumn (October 2010), for example, in the Black Forest at 1000m above sea level in a trail side verge on the edge of a large clearing.
Endangerment factors:
Many habitats are endangered about by grazing abandonment and subsequent reforestation or forestry operations (dark forest management). But Aplocera praeformata has overall not too high requirements and is therefore still not higher threatened.
Remarks:
Aplocera praeformata occurs in Europe in the mountains (missing in some places in the west and in both the far south and north). It is particularly common in the Alps.