Emerging stonefly, Perla bipunctata, as it leaves the final instar to become an adult. Taken on the River Wear at Stanhope stepping stones.

- Image ID: 2AGR2GF
Emerging stonefly, Perla bipunctata, as it leaves the final instar to become an adult. Taken on the River Wear at Stanhope stepping stones.
DAVID HIGGINS / Alamy Stock Photo
Image ID: 2AGR2GF