How to tell the Difference Between a Common Blue and a Holly Blue Butterfly?

How to Tell the Difference Between a Common Blue and a Holly Blue Butterfly??

Common BlueButterfly photo by Peter Withers (male/upperwing)

Holly Blue Butterfly photo by Iain Leach (male/upperwing)

 

I have both butterflies at home

The Common Blue which is the most widespread of the UK’s Blue butterflies, flies relatively close to the ground and I see it regularly in my garden and meadow areas

The Holly Blue emerges earlier in the year and I find it in my garden, which is its usual habitat, as the primary larval food plants of Holly and Ivy are in plentiful supply. It flies higher, at head height, usually around trees and shrubs

The Butterflies can be distinguished when settled, although both males look quite similar from above as illustrated in the photos – the Holly Blue has a thicker black trailing edge on the forewing. The females are much easier to identify from above, as the Holly Blue females have a very distinctive thick black band that covers 1/4 of the forewing from the trailing edge against the vivid blue background. In comparison the Common Blue female can almost appear brown, or a mix of brown and blue, with orange and black dotes that run near the edge of the wings

Both are a similar size and bright blue in colour

The underside of the butterflies are very different – the Common Blue has distinctive orange spots on the underwing of the males

Common Blue Butterfly Male Underwing Photo by Andrew Cooper 

 

Whereas the Holly Blue has black spots on the underwing of the males

Holly Blue Butterfly Male Underwing Photo by Iain Leach 

 

Happy butterfly watching!!!

Candida Hopkinson