There are four common and widespread species of white butterfly that are frequently seen in gardens and many other habitats.
These are the Large White, Small White, Green-veined White and Orange-tip. Despite being very familiar, the identification of these butterflies is not straightforward, and this blog aims to familiarise you with the distinguishing features of each so that you can accurately identify them.
Apart from the male Orange-tip, which is immediately recognisable by the bright orange tips of its forewings, all other individuals of these four species are easily confused. In essence they are bright white butterflies with black or dark grey wing-tips and often with dark spots on the wings too. The undersides of the wings may be creamy-white or have streaks or blotches of greeny-grey.
Golden rules
1. Size is not always a good characteristic to use for identification. As with humans, butterflies vary in size, so although most Large White individuals are bigger than Small Whites, they can occasionally be smaller. Black/grey spots on the wings are also not very helpful, as these vary between males and females as well as between species.
2. You will have to see the underside of the hindwing to be certain of the identification. This means that if you only see the butterfly fly past at a distance, it is very unlikely that you’ll be able to make a definite identification. You have to be patient and accept that it won’t be possible to identify every white butterfly that you encounter!
Step 1: Underside of the hindwing
The underside of the hindwing, which is obvious when the butterfly is perched with its wing closed over its back, will be one of three different colour patterns:
Plain (a creamy-white colour but with no obvious markings) = Large White or Small White (see Step 2)
Streaked (greeny-grey lines following the wing veins radiating out from the shoulder towards the outer edge of the wing) = Green-veined White
Blotchy (greeny-grey camouflage pattern all over the wing) = Orange-tip
Step 2: Wing tips
The pattern of the underside (described in Step 1) will enable you to identify Green-veined Whites and female Orange-tips with certainty. However, to distinguish Large White from Small White butterflies, you also need to see the wing tips on the upper side of the forewing.
Extensive black marks at the wing tips, with black colour continuing a long way along the outer edge of the wing = Large White
Less-extensive grey or black marks at the wing tips, with colouration only extending slightly along the outer edge of the wing = Small White
Other white butterflies
There are other white butterflies that live in the UK e.g. Wood White and Cryptic Wood White, and rare migrants such as the Black-veined White and Bath White. These are scarcer species and not covered by this brief guide and the rules above will not necessarily work in the presence of these other species.
Acknowledgement
The illustrations used on this webpage are from the Guide to Garden Wildlife by Richard Lewington and are used with his kind permission. www.richardlewington.co.uk
Richard Fox
Head of Science
Follow me on Twitter: @RichardFoxBC