Quick facts

Common name: stag beetle

Scientific name: Lucanus cervus

Family: Lucanidae

Habitat: woodland, especially oak woods, as well as parks and gardens

Diet: decaying wood as larvae, tree sap as adults

Predators: birds, bats and carnivorous mammals

Origin: native

What do stag beetles look like?

Adults: adult male stag beetles have characteristic antler-like mandibles and can grow up to a whopping 75mm in length. Females have much smaller mandibles and grow between 30-50mm. Both male and females have shiny black heads and thoraxes and brown chestnut-coloured wing cases.

Larvae: are large white grubs with orange heads and legs. They can grow up to 110mm long and live underground.

Not to be confused with: a lesser stag beetle. The female stag beetle and this species look familiar, however the lesser has a squarer shape and is matt black all over.

Credit: Arterra Picture Library / Alamy Stock Photo

What do stag beetles eat?

Adults: survive solely on tree sap and energy stores from their larval stage.
Larvae: spend their development munching on deadwood underground, building up enough energy to emerge and mate when they reach adulthood.

Did you know?

The cocoon of a stag beetle can be as large as an orange.

How do stag beetles breed?

Male stag beetles use their huge mandibles to fight off rival males and impress potential mates. After mating, the female will leave to find some deadwood where she will dig her way underground and lay up to 21 eggs.

Eggs are laid in the summer and hatch into larvae that will remain underground feasting on decaying wood, shedding their skin five times, until they grow large enough to pupate. Depending on the weather, this process can take between three to seven years.

When a larva is ready to mature, it will cocoon before emerging in adult form in May. Adult beetles have a short life-span and will die soon after mating, usually by the end of August.

Credit: William Harvey / Alamy Stock Photo

Where do stag beetles live?

Stag beetles are largely confined to southern England and are rarely seen further north. They prefer oak woodland, but you’ll also find them in more built up areas in parks and gardens, provided there is plenty of tree cover.

Did you know?

In European folklore, stag beetles were thought to summon thunder and lightning.

Signs and spotting tips

Listen out for the loud droning buzz of the male as it flies in search of a mate on a warm summer’s night. As well as being huge and loud, you can identify a stag beetle from its strange flight - upright with its wings out behind. You might spot a female crawling on the ground in wooded areas looking for a place to lay its eggs.

Credit: Frank Hecker / Alamy Stock Photo

Threats and conservation

Stag beetles are suffering from a loss of habitat. The UK has lost much of its native broadleaved woodland and decaying wood is often removed, leading to a decrease in the natural resources stag beetles rely on. We ensure that there is plenty of deadwood on our sites to support biodiversity. These beetles are often killed by cars as they are attracted to the heat of warm tarmac, and some are mistakenly seen as dangerous and killed. If you see a stag beetle in the road, carefully pick it up (if it’s safe to do so) and move it to a safer spot.

Did you know?

Stag beetles are considered a pest in the Middle East where they dig into the root systems of date palms, affecting the date crop.