Summer Azure

Celastrina neglecta · Butterflies

Summer Azure in flight

Brooklyn Botanic Garden, 19 August 2026

A Summer Azure in the air between leaves in the August border at the Botanic Garden, wings open, which is a view this butterfly almost never gives when it lands. It is one of the commonest small butterflies of the eastern woods and their edges, and one of the smallest in the garden, with a wingspan of about two and a half centimetres.

At rest it keeps the wings shut, showing only the chalky grey underside with its fine chain of dark dots along the margin. Here the wings are pale enough in the light to read as nearly white, with a hint of the blue above. Several broods a year carry it from spring into early autumn, which is what separates it from the near-identical Spring Azure.

Summer Azure on virgin's bower

Brooklyn Botanic Garden, 19 August 2026

A small blue working the small white flowers of virgin's bower, a native clematis vine, in the August border. The azures are butterflies of the eastern woods and their edges, and a late-August one in Brooklyn is the summer generation on one of its last flowers.

August timing points to Summer Azure over its near-identical spring counterpart, but the azures remain a genuinely difficult group. Several look-alike species overlap in range and season, and a fully confident call usually wants a look at the wing undersides in better light than this.

Summer Azure, upperwing

Brooklyn Botanic Garden, 26 July 2026

A male Summer Azure with the wings spread flat to the sun in the July border, showing the powder blue of the upperside that is otherwise only a flash in flight. Azures are small butterflies of the woodland edges of the eastern United States, and a sunny garden bed in July is where the summer brood basks.

Small blues bask like this mainly to warm the flight muscles before feeding, not to be seen - courtship in this group runs largely on scent rather than on the colour that catches a human eye. The narrow dark edge to the forewing marks a male; a female carries a much broader dark border.

Summer Azure, underwing

Brooklyn Botanic Garden, 26 July 2026

A Summer Azure at rest on a flowerhead in the July border with the wings closed, which is how this butterfly nearly always sits. Azures are small blues of the eastern woods and their edges, and the summer generation breeds on the flower buds of dogwood and viburnum in a garden.

The underside is pale grey-white, and the faint chain of dark spots along the wing margin is the main field mark separating it from the very similar Spring Azure, which flies earlier in the year and rarely overlaps with it on the wing. The blue of the upperside shows only in flight. Barely two and a half centimetres across, and easy to lose the moment it lands.

Summer Azure

Brooklyn Botanic Garden, 26 July 2026

A Summer Azure perched with wings closed in the late-July border, one of the smallest butterflies in the garden and one of the commonest across the eastern woods and their edges from June to September. The caterpillars feed on the flower buds of dogwood, viburnum and a dozen other shrubs.

The pale grey underside with its scatter of small black spots is the pattern that separates the Azures from the region's other small blues, though telling this species from its close relative the Spring Azure by sight is genuinely difficult and mostly comes down to season. A late-July date makes Summer Azure the safer call.