Yellow Shell Camptogramma bilineata
Wingspan 20-25 mm.
A very variable species, with examples ranging from bright yellow through to dark brown, and also variable in size. Four different subspecies occur, with the smaller and darker ones frequenting rocky places in northern Scotland and Ireland.
It is quite common throughout Britain, occupying a range of habitats, but with a preference for damper areas.
It has one generation, flying from June through to August, and the larvae feed on a variety of low-growing plants, including chickweed (Stellaria media) and sorrel (Rumex).