Rare stag beetles, which are the largest in the UK, have been discovered in 30 per cent of Surrey gardens surveyed this summer.
The beetles, which grow up to 8cm in length, are losing their natural habitats due to tidying up of fallen wood in parks, gardens and forests, which their larvae need to eat and develop.
The beetles are now largely confined to the south-east of England.
The Royal Society for the Protection of Birds is urging people to help preserve the species by leaving dead wood on the ground or by putting buckets of suitable logs in soil in a garden or on a balcony.
The conservation charity surveyed gardens with the help of Surrey residents who took part in their summer wildlife survey between June 4 and 12.
People were asked to report sightings of the threatened bugs, along with other garden visitors such as birds, frogs and foxes.
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