Polyommatus artaxerxes (Fabricius, 1793)

Host plants:
Only rock rose (Helianthemum) can currently be considered as a secured host plant in the field. But the species probably uses also Geranium and/or Erodium which are readily accepted in breeding.

Habitat:
Polyommatus artaxerxes inhabits (limestone) grasslands and mountainous meadows and pastures in the Alps and other, also lower mountain ranges from about 500m to 2500m above sea level with a peak between 1000 and 2000m.

Life cycle:
Polyommatus artaxerxes usually flies only in a single generation between June and mid-August. However, uni- and polyvoltine populations merge seamlessly into each other, so on the Swabian Alb, and especially in the lower elevations of the Alps at around 1000m asl. On 15/10/2005 I observed a newly hatched adult of a partial second generation even at 2100m above sea level in Rätikon (west Austria). The young caterpillar overwinters.

Endangerment: regionally endangered or decreasing

Endangerment factors:
Due to the loss of nutrient-poor grasslands, Polyommatus artaxerxes is endangered especially in the lower elevations. In the Alps, the butterfly is however often common and thus less threatened. The extent of damage due to global warming, which favours P. agestis, would be to determine, but a local displacement can be considered as likely.

Remarks:
Polyommatus artaxerxes is not completely separated from Polyommatus agestis. But nature can not be forced into rigid categories. So it is probably described best with the terminus semi-species.

Polyommatus artaxerxes is distributed from Northwest Africa (Atlas Mountains) across many mountain ranges in Europe, northern England, Scotland and Scandinavia to the Asian Altai.

Hints on determination:
Single specimens can not be determined reliably if the conditions of the site are unknown. Polyommatus artaxerxes is slightly larger, darker and shows smaller or even no orange lunules on the upper side, but the differences are subtle and fluent. But some northern populations (e.g. Scotland) show whitish central spots on the forewing uppersides.