Damon Blue

Polyommatus (Agrodiaetus) damon


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Polyommatus damon

Male, Switzerland, August 2013

Polyommatus damon

Male on ground and female in flight, Switzerland, August 2013

Polyommatus damon

With northern brown argus in flight and green-veined whites behind, Switzerland, August 2013

Polyommatus damon

Male, Switzerland, July 2017

Poplyommatus damon

Male, Switzerland, August 2013

Polyommatus damon

Female, Switzerland, July 2007

Polyommatus damon

Female, Switzerland, July 2007

Poplyommatus damon

Female, Switzerland, August 2013

Polyommatus damon

Males with chalkhill blue (left of centre) and idas blue (in flight), Switzerland, August 2013

Polyommatus damon

With green-veined whites, Switzerland, August 2013

Male, Switzerland, August 2008

Male, Switzerland, September 2008

Male, Switzerland, September 2008

Female, Switzerland, September 2008

Polyommatus damon

Female, Switzerland, September 2008

Switzerland, July 2005

Polyommatus damon distribution

Distribution

This is a lovely butterfly of high and late summer in mountainous regions of Europe, though its distribution is restricted to the southern half of the continent. From July onwards it may be seen in flowery grassland, scrub and open woodland where its foodplant, sainfoin, grows. It is said to fly from 1000m but in Switzerland I have seen it much lower than this, not far above the valley floor, at about 600m. Males in particular love to gather with other butterflies at damp spots to sup minerals. Females are often seen in the vicinity of the foodplants.

The male is gleaming sky blue above with broad, dark margins leaking inwards along the veins. The female is all brown, usually with a very few blue scales at the wing bases. Both sides have a srong, clear, white stripe on the underside hindwing, extending from the base to the submarginal region. In the Alps it is the only blue with this feature, making it very easy to recognise. The female underside is a deep chestnut while the male is a lighter shade of tan.

The Damon blue hibernates as an egg or first instar larva in most of its range. Given that it is a montane species, this explains its relatively late emergence in the season.