Unexpectedly, butterflies’ vibrant wing colours play no part in mating but scent is crucial. The green-veined white’s scent, citral, consists of two isomers, geranial and neral; both are needed for the males to successfully woo a partner. They waft this aphrodisiac pheromone around throughout their life to attract females and repel rival males. Females release their own scent to inform the male she is ready to mate too.

— Read more in Old cigar box or zesty lemon: the sweet scent of butterfly romance at The Guardian.