White-letter Hairstreak
Overview
 
The White-letter Hairstreak (Satyrium w-album) is a butterfly
Butterfly
A butterfly is a mainly day-flying insect of the order Lepidoptera, which includes the butterflies and moths. Like other holometabolous insects, the butterfly's life cycle consists of four parts: egg, larva, pupa and adult. Most species are diurnal. Butterflies have large, often brightly coloured...

 in the family Lycaenidae
Lycaenidae
The Lycaenidae are the second-largest family of butterflies, with about 6000 species worldwide, whose members are also called gossamer-winged butterflies...

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A dark little butterfly that spends the majority of its life in the tree tops, feeding on honeydew
Honeydew (secretion)
Honeydew is a sugar-rich sticky liquid, secreted by aphids and some scale insects as they feed on plant sap. When their mouthpart penetrates the phloem, the sugary, high-pressure liquid is forced out of the gut's terminal opening. Honeydew is particularly common as a secretion in the Hemipteran...

, making it best observed through binoculars. The uppersides are a dark brown with a small orange spot in the bottom corner of the hindwing. The male has a small pale spot on the forewings made up of scent scales. The undersides are a lighter brown with a thin white line, the 'hairstreak' which gives this group of butterflies their name.
 
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