From March onwards keep your eyes peeled for a Brimstone.They’re easy to spot because they are BRIGHT, BRIGHT YELLOW!
So how come they look green in our photos? Well it’s the upper-sides of the wings which are bright yellow and you see those when they’re flying around, but when the butterfly lands it ALWAYS folds it’s wings so you can only see the under-sides, which are sort of milky-green.
Brimstones are often the first butterfly seen in spring because they hibernate as adults, often tucked away in some ivy, whereas most butterflies hibernate as an egg, a catapillar or a chrysalis and don’t become adults until the summer.
DID YOU KNOW: the caterpillars of brimstone butterflies can only feed on the leaves of BUCKTHORN and ALDER BUCKTHORN trees. The butterflies seem MUCH more common than the trees are - but that’s mostly because both these tree species are pretty low-profile - you could easily walk past one and not even notice, so there are more of them around than you might think!