Bumblebee Conservation Trust is calling on ‘citizen scientists’ to search for the great yellow bumblebee, which is found only in the far north and on some islands.
The species used to be widespread across the UK but has suffered massive declines since the 1960s.
It has already disappeared from 80 per cent of its former territories across the country.
The remaining colonies live in machair grasslands and other flower-rich areas in Tiree, the Uists, Harris, Lewis, Caithness and Sutherland, Orkney and Shetland.
But because many of the areas are remote and relatively uninhabited, the species is difficult to monitor – leaving experts uncertain about exactly where it still survives.
Now nature-lovers can help rescue the insect from the brink of extinction.
They are asking people to hunt for the great yellow in 28 specific places to create a clearer picture of how many of the endangered bees are left.
Katy Malone, Scotland conservation officer for the Bumblebee Conservation Trust, said: “We need to know more about where the great yellow bumblebee is holding on, so we can take action to protect it before it’s too late. Anyone can get involved with this citizen science initiative to save a species.
Because this iconic insect’s last havens are in some of the country’s most far-flung corners, we don’t have enough volunteers to find and record its whereabouts.
“So we’re asking people holidaying in the north-west Highlands and islands this year, as well as those living in these beautiful places, to help.”
The great yellow is a large bumblebee. It is entirely covered with golden-yellow hairs, apart from a black band across the thorax between the wings.
The charity is asking people to record what they see and to take photographs if they think they have found a great yellow. This will help experts confirm identification.
Good places to search for specimens are areas of flower-rich grassland, particularly those with clover, thistles, vetches and knapweed – ideally when the weather is sunny, warm and not too windy.
The great yellow bumblebee is a late emerging bumblebee. Queens are usually seen from mid-June, when they will feed on nectar and begin to search for a suitable nest site.
They will use old mouse nests, rabbit burrows and other holes under grass tussocks as nest sites.
The Great Big Great Yellow Bumblebee Hunt begins this Saturday and features 28 grid squares where the species has been known to live, but which have not been checked in recent years. Anyone who wants to take part in the project should visit the Bumblebee Conservation Trust website for instructions – www.bumblebeeconservation.org – and a map of the search areas.
The UK’s bumblebee populations have crashed during the past century, with two species having gone extinct.
Loss of habitat – including at least 97 per cent of wild flower meadows – is the biggest threat to the survival of these important pollinators.
Climate change, disease and pesticides may also be major threats.
Today 24 bumblebee species remain, several of which have declined dramatically.