Compare with: gatekeeper

Brown hairstreak Thecla betulae

Vulnerable


Best time to see: late Jul to end Sep

Key facts

An elusive golden hairstreak butterfly that spends most of its time feeding or congregating in the treetops

Habitat: around large ash trees or laying eggs nearby on blackthorn or related species, such as wild cherry

Restricted to southern England and west Wales

Recognition

Golden underwings crossed by thin white lines and with a distinct tail; 38–40mm; usually perch with closed wings

Congregate around large ash trees in high summer, drinking honeydew from aphids and looking for mates

Males rarely leave the treetops, but females disperse to lay eggs

Lifecycle

After mating, females descend to lay eggs singly low down on blackthorn or other shrubs

Caterpillars are triangular, pale green with yellow stripes

They pupate in July, emerging as adults from late July onwards


© Charles J Sharp