Chersotis margaritacea (de Villers, 1789)

Host plants:
The larvae feed on Galium and Asperula species that grow on rocks or rock.

Habitat:
Chersotis margaritacea inhabits rocky slopes, boulder fields and gappy, stony places that are rich in fine substrate.

Life cycle:
The caterpillar overwinters and feeds at night in older instars when the temperatures allow this (often already at around -2 degrees Celsius). It grows in the autumn and early spring and backtrack into the pupation place in March or April, in the highest elevations probably until early May. In Valais, I found mature larvae in mid-April 2009 at 1000m above sea level together with small Chersotis multangula in a partially shaded, bushy spot in a rocky steep slope. They were superficially digged in the fine substrate during the day and betrayed themselves by eroded Galium-shoots. The moths fly mainly in July and August, rarely earlier or even in September in the higher mountains.

Endangerment: strongly endangered

Endangerment factors:
Chersotis margaritacea is threatened mainly at lower altitudes due to overgrazing and destruction of the economically worthless habitats (agriculture, overbuilding).

Remarks:
The distribution extends from Morocco across Southern and Central Europe (up to the central German Uplands) to Kazakhstan.