Dateline: Good Friday, 25th March 2016 - my first Brimstone of the year, a golden buttery-yellow in colour flitting through the garden, surely a sign of Spring. I wondered on the rain soaked Saturday that followed how it would have faired. They are great survivors - its life would have started in May or June 2015 as an egg laid on a sunny twig of a buckthorn bush in a hedge or woodland edge, the egg would have hatched after two weeks and our small green caterpillar would start to feed on the upper surface of a buckthorn leaf. During July, now a fully grown caterpillar, it would pupate and form a chrysalis. A further two weeks and our fully grown Brimstone butterfly would emerge.

Next priorities would be to feed up on nectar rich flowers ready to hibernate over winter, find a mate in March and April and thus start the life cycle once more. The male of the Brimstone is bright yellow, the female is a much paler green-white.