Hadena albimacula (Borkhausen, 1792)

Host plants:
The caterpillars live in Silene nutans and in Southern Europe also in a number of related Silene species (flowers, fruits). In Greece, I found many larvae of Silene paradoxa (which is also sticky, but much has larger fruits), Silene radicosa and other species.

Habitat:
Hadena albimacula colonizes rocky grasslands, rocky slopes, quarries, stony embankments in open forest (Greece), stony mountain pastures and other warm and dry locations of larval host plants. In the northern Alps, 2000m asl are hardly reached, in the Southern Alps, however significantly exceeded.

Life cycle:
Hadena albimacula has north of the Alps usually only a single, early flying generation from early May to late June. The pupa overwinters. The caterpillars can be found in the Swabian Alb from May to early July. Larvae from there result also in breeding only very rare in a partial second generation. In the Alps, caterpillars can be observed still in August. Here - kept warm - more adults of a second generation can be obtained, as would probably occur in the field only in exceptional cases. Silene nutans blooms early from May to early July on the Swabian Alb, and then practically no more.

In Southern Europe (as in parts of Greece), Hadena albimacula occurs in usually two generations in lower and medium altitudes and in a single generation only in high elevations.

Endangerment: endangered

Endangerment factors:
In the Alpine regions as well as in Southern European mountain ranges, Hadena albimacula is in the medium high altitudes (in lower it has fairly been pushed back) besides Hadena caesia the most common Hadena-species and is missing hardly a larger, dry sunny Silene nutans site.

In the lower mountain regions north of the Alps (e.g. Jurassic Alb Mountains in Southern Germany) the few populated locations mainly on rocky slopes and old quarries are, however, under serious threat. Causes are overgrazing during the blossom time of Silene nutans, succession (bush encroachment and reforestation after abandonment) and excessive tourist use of the small-area locations. Also reclamation of quarries or large-scale modern quarries can lead in some cases to extinction.

Remarks:
The overall distribution ranges from North Africa across most of Europe to Central Asia.