A black-spotted longhorn beetle resting on a leaf
Black-spotted longhorn beetle © Brian Eversham

Black-spotted longhorn beetle

Rhagium mordax

Statistics 
Length:13mm - 23mm

These bulky beetles can sometimes be found on flowers in woodland rides or along hedgerows.

About

The black-spotted longhorn beetle is found throughout most of the UK. They're usually seen in woodlands, or along hedgerows. The adult beetles often visit flowers to feed on nectar and pollen, particularly hawthorns and umbellifers. Female beetles lay their eggs on fallen dead wood, old stumps, or decaying trees. The larvae live beneath the bark, feeding on rotting wood. They can spend two or three years in this stage, before creating a little chamber of wood fibre in which to pupate. They pupate in late summer or early autumn, but the adults stay within their pupal chamber until spring.

How to identify

A mottled yellowish-brown and black beetle. It has two large black spots on its wing cases, with a pale band either side of each spot. The antennae are relatively short for a longhorn beetle.

Did you know?

The larvae of this beetle contain antifreeze proteins that help them survive cold winters.