Male. Taken at Crog Hill, Oxon., on June 5th 2021. (© David Hastings)
(1/640th sec at f11)

Male underside. Taken at Aston Rowant NNR, Oxon., on August 17th 2023. (© David Hastings)
(1/800th sec at f11)

Female. Taken at Lardon Chase, Berks on August 17th 2017. (© David Hastings)
(1/800th sec at f13)

Female underside. Taken at Lardon Chase, Berks, on August 17th 2017. (© David Hastings)
(1/4000th sec at f13)

Mating pair. Taken at Aston Rowant NNR, Oxon, on August 29th 2016. (© David Hastings)
(1/200th sec at f13)

Description

Family: Polyommatinae

Wing span: 30 - 40 mm

Adonis Blue sexes are strongly dimorphic; the males are a brilliant blue, and the females are chocolate brown. There are 109 named aberrations known to occur in Britain. Occasionally hybridisation occurs with the Chalk Hill Blue.

This species is restricted to the south and east of England. It is found on chalk and limestone grassland where the turf is short. It is widespread and locally common in C and S Europe.

There are two broods each year. The first adult emergence is in the second half of May, peaking at the end of May and beginning of June. The second adult emergence is in the second half of August, peaking at the end of August and beginning of September. The larva is the over-wintering stage. Larvae are often attended by a species of red ant (Myrmica sabuleti) or black ant (Lasius alienus).

The sole larval food plant is Horseshoe Vetch.

Adults feed primarily on Marjoram and Ragwort.

The female Adonis Blue can easily be mistaken for a female Chalk Hill Blue. One guideline is that the pale scales on the hindwings, between the red dots and the white fringe, are blue in a female Adonis Blue and white in a female Chalk Hill Blue.

Near Threatened

Earliest UK sighting: 20th May ; Latest UK sighting: 31st August

Sightings