Holly Blue (Celastrina argiolus)
Holly Blue (Celastrina argiolus)

Holly Blue (Celastrina argiolus)
Family: Lycaenidae
Subfamily: Polyommatinae
Tribe: Polyommatini
Genus: Celastrina
Species: argiolus
Subspecies: britanna

Key ID Features:
Lilac-blue wings of male have thin black borders, thickening toward the tip of the forewings, with chequered white fringes.
Lilac female upperside has broad, black bands on fore and hind wings.
Both sexes have silvery-blue underside, finely speckled with black but no trace of orange.

Seen in UK: April-September

The Holly Blue is primarily found in the southern half of the British Isles, and is a frequent visitor to gardens. This species is renowned for fluctuating wildly in numbers, forming a predictable cycle over a few years, believed to be caused by parasitism from the wasp Listrodomus nycthemerus whose sole host is the Holly Blue. The wasp lays its eggs in Holly Blue larvae, with a single adult wasp eventually emerging from the Holly Blue pupa. In England and Wales this species is widespread and common, south of a line running from Cumberland in the west to County Durham in the east. This species is also found on the Isle of Man and throughout Ireland, but is absent from Scotland except as a scarce vagrant.

Text (c) UK Butterflies, used with permission
For more information click here

Photographer: Tim Tapley

Holly Blue (Celastrina argiolus)

Holly Blue (Celastrina argiolus)
Family: Lycaenidae
Subfamily: Polyommatinae
Tribe: Polyommatini
Genus: Celastrina
Species: argiolus
Subspecies: britanna

Key ID Features:
Lilac-blue wings of male have thin black borders, thickening toward the tip of the forewings, with chequered white fringes.
Lilac female upperside has broad, black bands on fore and hind wings.
Both sexes have silvery-blue underside, finely speckled with black but no trace of orange.

Seen in UK: April-September

The Holly Blue is primarily found in the southern half of the British Isles, and is a frequent visitor to gardens. This species is renowned for fluctuating wildly in numbers, forming a predictable cycle over a few years, believed to be caused by parasitism from the wasp Listrodomus nycthemerus whose sole host is the Holly Blue. The wasp lays its eggs in Holly Blue larvae, with a single adult wasp eventually emerging from the Holly Blue pupa. In England and Wales this species is widespread and common, south of a line running from Cumberland in the west to County Durham in the east. This species is also found on the Isle of Man and throughout Ireland, but is absent from Scotland except as a scarce vagrant.

Text (c) UK Butterflies, used with permission
For more information click here

Photographer: Tim Tapley