Small White

Fascinating facts about the Small White

• A female Small White lays 300 eggs in her lifetime, but only if she finds the right plant—cabbage or broccoli. She tastes leaves with her feet, detecting mustard oils through chemoreceptors on her legs that are 100 times more sensitive than human taste buds. A single wrong plant choice wastes the egg and dooms the caterpillar before it hatches.
• In just 3 weeks, a Small White caterpillar grows 3,000 times heavier than the egg it hatched from. If a human baby grew at the same rate, it would weigh 150 tonnes by its first birthday—as heavy as a blue whale.
• Small Whites invaded North America in the 1860s, possibly hidden in shipments of cabbage seeds from Europe. Within 40 years they spread from Quebec to California, becoming one of the fastest-expanding butterfly populations ever recorded. Today they're so abundant that farmers spend millions spraying pesticides to stop them eating crops—a species that went from zero to pest in a single generation.
• Males patrol open fields at around 10 km/h, hunting for females by looking for the scent of pheromones released from glands on the female's wings. A male can detect a single pheromone molecule from over 100 metres away, then chase the female through a zig-zag dogfight that lasts seconds before mating.
• A Small White's wings are covered in scales arranged like roof tiles, layered so tightly that water rolls straight off. But the real magic is invisible: the scales bend light in a way that makes the white colour appear brighter than white pigment alone ever could. This structural colour is the same physics that makes oil slicks shimmer—the butterfly invented it 100 million years before humans discovered the principle.

At a glance

About the Small White

As the Small White butterfly dances through the garden, its delicate wings beating in a hypnotic rhythm, it weaves a trail of gentle wonder, its creamy hues glistening like freshly fallen snow. With an effortless elegance, it alights upon a tender bloom, its proboscis uncoiling like a slender thread to sip the sweet nectar within, its very presence a testament to the beauty of impermanence. In its fleeting, whirling journey, the Small White embodies the carefree essence of summer itself, a tiny, winged embodiment of the season's warmth and vitality.

Discover more wildlife