Rare beetle that oozes substance from its knees when attacked rediscovered in Wales | Insects

A rare beetle has been rediscovered in Wales after nearly 60 years, conservationists have said.

The short-necked oil beetle, driven to the brink of extinction in Britain due to habitat loss over the course of the 20th century, has been found at the Castlemartin range in Pembrokeshire, according to Natural Resources Wales (NRW).

The species’ name comes from the adult beetles’ stubby shape and ability to secrete an oily yellow-orange substance from their knee joints when alarmed.

The unusual creature relies on solitary bees and thick vegetation and flower coverage to survive. Its larvae have hook-like feet to snag on to bees, and once in their nest, they feed on pollen until ready to emerge as adults, with a lifespan of about a year.

Only a handful of sites in the UK are suitable for the beetle, according to NRW, and only about one in 10,000 larvae make it to adulthood. It is classed as nationally rare.

The bug was rediscovered in Devon in 2006, and populations have since been found in the Hebrides and on Salisbury Plain.

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The nature conservation charity Buglife reported the beetle was found at the Pembrokeshire site in 2020, but surveys carried out in 2022 and 2025 only found dead adults, raising concerns about the species’ viability in the area.

However, the 2026 survey discovered larvae distributed in such a way to suggest hatchlings from a larger batch of immature beetles had thrived.

Anna Hobbs, the project delivery officer for the Bumblebee Conservation Trust, said finding evidence the species was breeding again was very exciting.

“The short-necked oil beetle is an amazing creature and not only depends on a very specific habitat to survive, but the presence of solitary bees as well. So, the work we do needs to consider the needs of several species to be effective,” she said.

“We are very grateful to our partners and volunteers for persevering with us after two years without larval sightings and look forward to the continued management of the site so that this amazing species can survive now and into the future.”

The beetle project, part of Wales’s flagship species recovery programme, Natur am Byth, is working to conserve several endangered animals and plants that share similar habitats to the short-necked oil beetle, including the shrill carder bee, goldilocks aster and pale dog violet.