(Knoch, 1782)
White-letter Hairstreak
Description:
The White-letter Hairstreak usually occurs where there is a group of elm (Ulmus spp.) trees, either growing in a wood, or apart, sometimes even in the centre of a large town. However, there are populations known that occupy a solitary tree.
The eggs are laid on the wood at the base of the flower buds, the female favouring terminal buds situated at the top of the tree. The small caterpillar stays inside the egg during the winter months, emerging in the spring, boring its way into a flowerbud. It feeds on flowerbuds and flowers, but not on leaves. A non-flowering tree is therefore not a suitable food plant. The caterpillars pupate in the litter layer under the tree.
The White-Letter Hairstreak has one generation a year.
Habitat:
Tree lines and hedges
Mixed woodland
Urban parks and gardens
Deciduous forests
Similar species:
Satyrium pruni
Satyrium spini