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.