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A large emerald moth resting with its wings spread

Large emerald © Brian Eversham

A large emerald moth resting on a leaf

Large emerald © Vaughn Matthews

Large emerald

Scientific name: Geometra papilionaria
This large green moth rests with its wings spread, so is sometimes mistaken for a butterfly.

Species information

Category

Statistics

Forewing length: 24-29mm

Conservation status

Common

When to see

Adults: June to August

About

The large emerald is a big green moth found throughout most of the UK. They live in a wide range of habitats, particularly woodland, and scrubby grassland and heathland, but also parks and gardens. They fly at night and are attracted to lights, but will occasionally fly around tree canopies on sunny days.

Large emerald caterpillars appear in late summer and feed on alder, beech, and birch trees. They spend the winter as a caterpillar, sitting on a silk pad on a twig of their foodplant. They are already well camouflaged, but hide themselves even more by placing tiny, chewed-up pieces of bark on their body. They become active again in spring, feeding amongst the foliage. When they're fully fed, they pupate amongst leaf litter on the ground, ready to emerge as adults in summer.

How to identify

A large, green moth with wavy-edged wings. There are wavy white lines running across the wings. They rest with their wings spread open and slightly raised, like many butterflies.

Caterpillars are green or brown and speckled with fine white dots. They have a series of bumps along the back.

Distribution

Widespread and common throughout most of mainland Britain and the Inner Hebrides, as well as Northern Ireland. Local on the Isle of Man, rare in the Channel Islands.

Habitats

Did you know?

Large emeralds are attracted to the lights of moth traps (used to survey the moths in an area), but will often land on plants or other structures a few metres away, rather than entering the trap.