The few Brimstones I’ve seen so far this year – just three before today – have been buttery yellow males and have raced past at the speed of light, spreading their pheromones and patrolling their chosen area in the hope of finding themselves a female. Though determining their colour can sometimes be tricky without the other gender for comparison, I think today’s Brimstone, with its paler, more greenish-lemon colour, was a female. She was certainly hungry, happy to linger and make the most of the lush Dandelions.