- Lifespan
- 2–4 weeks as adults; larvae overwinter and can remain dormant for extended periods
- Size & Weight
- Wingspan 24–28 mm
- Habitat
- Open heathland, grassland, and moorland with low-growing vegetation, particularly areas with bird's-foot trefoil and gorse.
- UK Distribution
- Resident and locally distributed across southern England, Wales, and scattered populations in the Midlands and Southwest. Absent from northern England and Scotland. Resident with single or double broods depending on location and weather.
- Diet
- Larvae feed primarily on bird's-foot trefoil and other Lotus species; adults feed on nectar from low-growing flowers.
- Predators
- Birds, spiders, parasitic wasps, and small reptiles
- Mating Season
- May to August (June to July peak)
- Breeding
- Females lay single eggs on host plants; larvae develop through summer and overwinter as pupae or late-instar larvae. Two generations per year in southern populations, one in northern range.
- Behaviour
- Males are highly territorial, perching on vegetation and chasing rivals; they engage in a distinctive 'patrolling' behaviour to locate females. Males possess characteristic silvery spots on the underwing that give the species its name. The species is closely associated with specific foodplants and ant species that tend larvae.