Quick facts

Common name(s): forest bug, red-legged shieldbug

Scientific name: Pentatoma rufipes

Family: Pentatomidae

Habitat: oak and broadleaf woodland

Predators: birds, reptiles, amphibians

Origin: native

What do forest bugs look like?

Forest bug larvae are tiny, dark bugs that become lighter as they develop.

The adults grow to a length of 1.1 to 1.4cm and are shield-shaped and shiny with broad, spiked shoulders. They have a dark brown body during autumn and a paler, bronze-coloured body in summer. Look out for distinctive red-orange legs and an orange spot on the back.

Don’t confuse for: other shield bugs. Forest bugs have much sharper ‘shoulders’ than other species, a bit like an 80s power suit!

Did you know?

Forest bugs are considered a pest by some farmers and gardeners as they have a taste for fruit and nut trees.

What do forest bugs eat?

The forest bug’s diet is predominantly made up of the sap of deciduous trees such as oak, alder and hazel. They use their mouthparts to pierce the veins of the tree and draw out the sap. Some adults feed on fruit or may even be partly predatory, feeding on caterpillars and other insects.

Did you know?

Forest bug eggs look like little smiley faces.

How do forest bugs breed?

Breeding takes place in summer for forest bugs. Females lay eggs on the bark of oak and other deciduous trees during August. The eggs hatch into young nymphs towards the end of August.

Nymphs go through several stages of moulting and overwinter in this form. They usually appear as fully grown as adults the following July.

Did you know?

Forest bugs are considered a pest by some farmers and gardeners as they have a taste for fruit and nut trees.

Where to find forest bugs

The forest bug is usually found in broadleaved woodland and gardens across the UK, particularly where there are oak trees, from July to November.

Credit: Blinkwinkel / Alamy Stock Photo

Signs and spotting tips

Look out for forest bugs on leaves along woodland edges and hedgerows between July and October.