Spotlight on Green Hairstreak

 

The Green Hairstreak (Callophrys rubi) holds the distinction of being Britain’s only truly green butterfly. Some may say, 'What about the Dark Green Fritillary? They have green under-wings?' My reply would be that it's only 'greenish', as stated in Butterflies of the West Midlands. In contrast, the under-wings of the Green Hairstreak are a vivid shade of emerald and give this elusive little fast-flying butterfly its unique place.

It is a delight for enthusiasts and photographers alike. Its shimmering colour isn’t just for show: it provides excellent camouflage among the leaves and grasses where it's often found. There is a faint white line, hence 'hairstreak', but this can be a few dots or even absent. This species always alights with its wings closed, so the dusky brown upper-sides are rarely seen or photographed. Males and females look similar.

 

Despite its striking appearance, the Green Hairstreak is quite small (think Small Copper or Skipper) and tends to stay low to the ground, sometimes making it tricky to spot. It is widespread across the UK, favouring habitats such as heathland, grassland and woodland clearings (and so not commonly seen in gardens). Its flight period is usually from April to June (with notable July and even August records around the Malverns), when adults seek out nectar from wildflowers. Its requirements include the presence of suitable larval food plants such as gorse, broom or bird’s-foot trefoil, as well as sunny, sheltered spots for adult basking and mating.

It's always a pleasure to see the early adults emerging in April (older records show them emerging in March). One of my favourite go-to places is Glacial Boulder on Cannock Chase (Walk 8 in Butterflies of the West Midlands) and others mentioned in the book are Llanymynech Rocks (Walk 3) and Lea Quarry (Walk 6). There are many other places where you might come across this little gem but, unless you’re really looking, you'll never see it.

Conservation efforts are focused on maintaining suitable environments to ensure this unique green butterfly continues to brighten British landscapes for years to come.