A “spent” mayfly struggles in the surface film on Ireland’s Lough Sheelin. Its outspread wings are a clue to its life stage, as is the time of day—it’s evening, it has finished breeding, and its short life is nearly over. Trout will often focus on “spents,” not least because they represent an easier meal than the newly hatched “greens” that appear earlier in the day. Photo: Ben Etridge