- Lifespan
- 2–6 weeks as an adult butterfly; caterpillars develop over 3–5 weeks depending on temperature
- Size & Weight
- Wingspan 40–50 mm; wingspan is the primary measurement for butterflies
- Habitat
- Open, disturbed areas including gardens, allotments, farmland, and wasteland where cruciferous plants grow.
- UK Distribution
- Found throughout mainland Britain and Ireland; resident year-round with multiple generations, though populations peak in summer and autumn. Migratory individuals arrive from continental Europe in spring.
- Diet
- Adults feed on nectar from a variety of flowers including dandelion, clover, and mustard. Caterpillars feed exclusively on plants in the cabbage family (Brassicaceae) such as cabbage, broccoli, and wild rocket.
- Predators
- Birds (particularly robins and blue tits), spiders, parasitoid wasps, and ground beetles predate eggs, caterpillars, and adults.
- Mating Season
- March to October, with peak activity April to September
- Breeding
- Females lay 50–100 eggs singly on host plants; eggs hatch in 3–5 days. Caterpillar stage lasts 3–5 weeks; chrysalis stage 1–2 weeks. Multiple broods occur annually, typically 2–3 in the UK.
- Behaviour
- Small Whites are highly mobile, strong fliers that often visit gardens seeking cruciferous plants for egg-laying. Males patrol low vegetation searching for females with characteristic fluttering flight. They are one of the first butterfly species to emerge in spring.