Have you seen a stag beetle recently? I haven’t seen one of these spectacular insects for some time, excepting what may have been the crushed remains of an unfortunate insect that had been trodden underfoot. They need our help, for although stag beetles were once widespread they are becoming rare and are increasingly threatened throughout northern Europe due to habitat loss.

Stag beetles are the UK’s largest land beetles but rarely seen outside southern England. I clearly recall my first encounter with one of these impressive insects after moving south to Surrey.

Male stag beetle on roses
The stag beetle might look intimidating but is harmless to humans and poses no risk to living shrubs (Duncan Wright)

We can all help reverse their decline. If you happen to spot a stag beetle or its larva please report it via the Great Stag Hunt website (stagbeetles.ptes.org): this is an annual survey by the wildlife conservation charity People’s Trust for Endangered Species’ (PTES) that helps scientists see long-term trends and allows action to be taken where and when it is needed to help the species.

The males are easily recognisable, with huge antler-like jaws: these may look intimidating but they’re harmless to human beings. The males are 40mm to 70mm in length, including the “antlers” which they use to fight other males for access to females during the breeding season, much like a male stag deer uses its antlers (hence their name).

Females are smaller (30-50mm long) and have smaller “antlers”. They lay their eggs in dead wood or nearby soil.

Stag beetles spend most of their life cycle underground as larvae, large white grubs, sometimes up to 10cm in length, feeding only on decaying wood and the fungi it contains, so they don't pose a risk to living trees or shrubs. I recall they thrived among rotting pallets at the bottom of the garden of our former home.

Larvae are fully grown after three to five years, when they build a large cocoon in the soil where they pupate and metamorphose into an adult.

Adults emerge from the ground from late May into July in search of mates. Males are often spotted flying around gardens, parksand allotments on warm summer evenings, usually an hour or two before dusk. They can also be seen on walls and warm tarmac surfaces in urban areas, and in green spaces too, such as woodland edges, hedgerows and orchards.

Adults can’t feed on solid food, relying mainly on the reserves built up while developing as larvae. But they can use their feathery tongue to drink from sap and fallen soft fruit.

A great way to help stag beetles is to build a log pile or pyramid in your garden, using old logs, tree stumps or fallen branches, burying them upright in soil. This provides a vital food source for larvae as well as offering shelter and a place for females to lay their eggs.

After creating your log pile, record it online on the Great Stag Hunt website. This shows PTES where these important habitats are. The site also has lots of facts about stag beetles and their lifestyles.

With stag beetles becoming scarcer, the PTES stresses that it needs help to find where adults and their larvae are seen. So when you’re outdoors, especially during the evening, keep your eyes peeled for these beautiful beetles and report any you see on the Great Stag Hunt website (stagbeetles.ptes.org).

And please drop an email to the News & Mail with your sightings too.