Holly Blue
Celastrina argiolus
National Status
Widespread in England and Wales, range expanding northwards. Population trend 10 years to 2016 -61%; since 1976 +37%
West Midlands Status
Throughout the region but fewer records from west Herefordshire and north-east Staffordshire, range stable. Population trend 10 years to 2016 – slight decrease.
Holly Blue was recorded in 1094 squares in 2026
10 Year Trend Analysis
Habitat
Woodland rides and edges, hedgerows, parks and gardens. Prefers shrubby vegetation unlike the other blue butterflies.
Caterpillar Food Plant
The main foodplants are Holly (Ilex aquifolium) and Ivy (Hedera helix). Bramble (Rubus fruticosus), Dogwoods (Cornus spp.), Gorses (Ulex spp.), Snowberries (various) (Symphoricarpos spp.) and Spindle (Euonymus europaeus)
Refer to the Gardening for butterflies website by Joseph Shaffery for more details about caterpillar food plants and nectar sources.
Life Cycle
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |||||||||||||||||||||||||||||||||||||
| Egg | ||||||||||||||||||||||||||||||||||||||||||||||||
| Larva | ||||||||||||||||||||||||||||||||||||||||||||||||
| Pupa | ||||||||||||||||||||||||||||||||||||||||||||||||
| Adult | ||||||||||||||||||||||||||||||||||||||||||||||||
Flight Period
Two generations, April to early June, July to early September.
First/Last Sightings 2026
| First Sighting | Recorded by | Last Sighting | Recorded by |
| 4 March | Young, Jean | 16 October | Corfield, Robert |
Distribution Map
Key
Total number of sightings per tetrad
Hotspots
In almost any of its preferred habitats.