Diarsia rubi (Vieweg, 1790)

Host plants:
The larvae are polyphagous in the grass and herb layer and also use low-growing shrubs like Vaccinium or Rubus. Obviously they often use Poaceae like Dactylus glomerata.

Habitat:
Diarsia rubi inhabits humid to mesophilous forb communities, woodland edges, riparian vegetation and edges in often grove-rich wetlands. It is especially common in extensively managed wet meadows with some groves. In humid macro climates it also penetrates into drier habitats like pastures or meadow orchards.

Life cycle:
The larva hibernates. I found a still very small larva in a humid, forb-rich stream valley at the northern edge of the Alps (Adelegg, near Isny, 800 m) in the herb layer near the ground on the first of November 2020. This larva moulted once and hibernated then probably in the antepenultimate instar. It obviously has been the offspring of a late flying female. Otherwise the larva should overwinter in a later instar (penultimate). Hibernating larvae obviously have more moults than non-hibernating ones.
In NW-Germany (Ostfriesland near Esens) I recorded mature larvae during daytime deep in tufts of Dactylus glomeratus with feeding scars and openly feeding or resting on Juncus stems during night in late April 2022 (cool spring).
The moths occur in one or two generations between May and September. At higher elevations or cool sites most often only one generation mainly between June and mid-August is involved. At low elevations or warm sites there are usually two generations from May to early July and again from late July to September.

Remarks:
The often common species occurs from Europe across the temperate zone to east Asia. In southern Europe it misses largely or is restricted to mountains.