Small Blue (Cupido minimus)

Family: Lycaenidae Checklist: 61.010

 
Description
Wing span: 18-27 mm. The Small Blue is the smallest British butterfly. The sexes are similar in appearance, although the male upperside is dark grey with a dusting of blue scales, whereas the female is more dark brown in colour. Both sexes have white fringes to their wings. The underwing is very distinctive, being silvery-grey with a scattering of small black dots, and lacking any orange markings (the Holly Blue is superficially similar, but is larger and has pale blue underwings). This butterfly is mainly found in southern England and South Wales, but there are also colonies in the English midlands and northern Scotland. Most colonies are on downland or in quarries, but they are also found on road and railway verges. Sheltered sites with sparse vegetation are preferred, as these conditions suit the larval food-plant.
 
Images (click to enlarge)
Small Blue ♂ © David Hastings
Small Blue ♂ underside © David Hastings
Small Blue ♀ © David Hastings
Small Blue ♀ underside © David Hastings
Male Male underside Female Female underside
 
Life Cycle
The larva is the over-wintering stage, pupating in April and May. Adults generally appear in early May at southern sites, reaching a peak at the end of May and beginning of June. There is a partial second generation in southern England, with adults appearing in late July and August.
 
Larval Foodplants
The only known larval food-plant in the UK is Kidney Vetch (Anthyllis vulneraria). The larvae live in the flower heads, where they feed on developing anthers and seed.
 
Nectar Sources
Adults will visit flowers such as Bird's-foot Trefoil and Kidney Vetch.
 
UK Conservation Status
Near Threatened
 
Earliest UTB first sighting (since 2004) : 21st April
Mean UTB first sighting (since 2004) : 7th May
 
Species Champion
Andy Spragg
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Reports
 
Distribution and Sites
 

Key
1 sighting 2-9 max seen 10+ max seen
This species is a habitat specialist. It can be found at these sites:
Berkshire
Lardon Chase
Seven Barrows
Buckinghamshire
Blue Lagoon
Bradenham
College Lake
Grangelands
Holtspur Valley
Incombe Hole
Pitstone Quarry
Oxfordshire
Aston Upthorpe Downs
Crog Hill
Hackpen Hill
Swyncombe Downs

 
Related Species
All Species