PICK OF TODAY’S RADIO

METAMORPHOSIS — HOW INSECTS TRANSFORMED OUR WORLD, 1.45PM, RADIO 4

MORPHO butterflies (pictured) are among the largest in the world, with a wingspan of up to eight inches. You would think from looking at them that their wings were coloured blue, but you’d be wrong. There is some black pigment in the shimmering wings, but the blue effect comes from refracted light bouncing off criss-crossing ridges. In this first of a new series, the entomologist Erica McAlister looks at a collection of Morpho butterflies held in Norwich Castle, and marvels at their iridescent beauty.