The Small Tortoiseshell is a medium-sized, pretty butterfly common in gardens where it feeds on Buddleia and other flowers. It is on the wing throughout the year, having several broods, and overwinters as an adult. Normally a very common butterfly, the Small Tortoiseshell has declined by 80% since 1990 in south-east England. Their decline has been blamed on wet summers bought about by climate change and the arrival of a tiny parasitic fly, Sturmia bella (first noted in Britain in 1999), which kills tortoiseshell caterpillars after they inadvertently eat its eggs. The caterpillars feed on Common Nettle.
How to identify
Unmistakeable: the Small Tortoiseshell is mainly reddish-orange in colour, with black and yellow markings on the forewings and a ring of blue spots around the edge of the wings. The similar Large Tortoiseshell is extinct in Britain.
Where to find it
Found right across the country.
When to find it
How can people help
Butterflies such as the Small Tortoiseshell will happily visit your garden and are a joy to watch. To attract Small Tortoiseshells into your garden, plant Buddleia bushes and nectar-rich borders for them to feed on, and leave patches of nettles for the caterpillars. For overwintering insects, plant climbing Ivy and shrubs. To find out more about encouraging wildlife into your garden, visit our Wild About Gardens website: a joint initiative with the RHS, there's plenty of facts and tips to get you started.