Chalk Hill Blue (Lysandra coridon)

 
 
Description
Wing span: 33-40 mm. The Chalk Hill Blue's sexes are strongly dimorphic, the males being a pale sky blue, and the females being a chocolate brown. The black markings on the male's wings are highly variable. The distribution of this species follows the distribution of Horseshoe Vetch which, in turn, follows the distribution of chalk and limestone grassland. This species is therefore restricted to England, south east of a line from the Wash to the Severn estuary.
Life Cycle
There is one brood each year with the adults emerging in the first half of July in typical years, with a peak being reached at the end of July and early August. The ovum is the over-wintering stage.
Larval Foodplants
The larval foodplant is Horseshoe Vetch.
Nectar Sources
Adults feed primarily on Bird's-foot Trefoil, Field Scabious, Selfheal, Thistles and Thyme.
UK Conservation Status
Near Threatened
Earliest UTB sighting (since 2004)
28th June
First sightings data
Species Champion
Nick Bowles (email: nick.bowles@ntlworld.com)
Sites
Aston Clinton Ragpits
Aston Rowant NNR
Aston Upthorpe Downs
Buttler's Hanging
College Lake
Dancersend
Grangelands
Hackpen Hill
Hartslock
Holtspur Valley
Ivinghoe Beacon
Lardon Chase
Lodge Hill
Prestwood LNR
Seven Barrows
Watlington Hill
Yeosden Bank