Euphydryas aurinia (Rottemburg, 1775)

Host plants:
In the wetland area, the caterpillars live mostly on Succisa pratensis, in the alpine region on Gentiana punctata, Gentiana acaulis and other gentians and Scabiosa lucida. In the Jura, the species lives in its few occurrences mostly on Scabiosa columbaria. Further the larvae occasionally feed on Knautia arvensis where I watched defoliation on a seasonally wet grassland in the Ammersee area (southern Bavaria) in the spring, and Knautia dipsacifolia (seen in forest gap systems of the Allgäu region around 1500m above sea level). Rarely, also other related genera are used as Menyanthes or in parts of the range (Spain) Lonicera (Caprifoliaceae), which is summarized with the Dipsacaceae (Knautia, Succisa, Scabiosa) to the order Dipsacales. But the Iberian and N-African populations are now regarded as E. beckeri. Interestingly, I found in May 2008 in the Engadine (Val Rosegg) at 2000m above sea level over 10 caterpillars that fed on the lower stems of Lonicera coerulea! Gentiana could not be observed within a distance of several meters.

Habitat:
Euphydryas aurinia occurs in many types of open landscape habitats. These all have in common that they are managed only very extensively and that they are quite nutrient-poor. Probably Euphydryas aurinia colonized originally many extensive grasslands in central Europe from the lowlands upt to high elevations in the Alps. There fly smaller, darker and less scaly specimens that were formerly separated as a separate species Euphydryas debilis.
Today Euphydryas aurinia is pushed back to marginal sites like fens on the one hand and dry grasslands on the other due to agricultural intensifications especially in the lowlands. Euphydryas aurinia requires low growing or only moderate high growing, not felted areas for development (host plant must stand freely and sunny at oviposition time) and avoids on the other hand also intensively grazed areas especially in the lower elevations.

Life cycle:
The caterpillar overwinters often as L4, rarely also as L3 (especially in the mountains). A repetitive, second overwintering of the caterpillars occurs partially in the plains and more often in the mountains. I found caterpillars and later pupae in the plains between March and May, in the mountains as late as early July. The pupae were often attached to the leaf upper side of Colchicum autumnale in a habitat. The adults fly from May to early July, in the mountains until August. Eggs are laid in clusters on the underside of leaves and was observed the author on Scabiosa lucida (Allgäu Alps), Succisa pratensis (Allgäu) and Gentiana acaulis (Swiss Alps). The young caterpillars and its webs are conspicuous in August/September on the plants.

Endangerment: strongly endangered

Endangerment factors:
Euphydryas aurinia is in very strong decline especially in lower and medium high elevations due to habitat loss because of intensification, afforestation, improper maintenance and isolation. This species tolerates neither a too intensific grazing nor abandonment of extensive maintenance (late mowing once in early autumn) for longer periods. The decisive factor is the correlation with the natural growth vigor of the habitat, i.e. in low and gappy growing sites there is no need of mowing annually, but stronger growing and more nutrient-rich sites should be mown annually and not too late. Changing, but only small (5-10% of the total area) fallow areas can be included in still large-scale nutrient-poor and low-growing habitats. Best would be a mowing in early or mid-September on fen meadows (Molinietum etc.). On vigorous sites a complete mowing even with rotary mowers can be tolerated under certain circumstances, at least in vital populations (A. Nunner personal information).

Thus the main problem for Euphydryas aurinia in the remaining habitats (especially on lowland Molinia grassland) is nutrient accumulation and subsequent felted vegetation after too late or missing mowing. Where there are already too high growing vegetation structures, regular mowing is essential already in early September. Smaller parts (20% of the total area) of the habitats could further benefit from an additional early mowing in early June in order to establish gappy and low-growing vegetation as it is needed for oviposition.


In the higher elevations of the Alpine region, Euphydryas aurinia is currently common and widespread in almost any mountain range (Southern Germany, Austria, Switzerland).

Remarks:
FFH species (Annex II).

The distribution extends from the Pyrenees across Europe and temperate Asia to Korea.

Today the southwestern populations of Euphydryas aurinia that has formerly been regarded as ssp. beckeri are treated as an own species (N-Africa, Iberian Peninsula).