75% of the most threatened bee species have been lost to some of the region's counties.
A report by nature conservation charity Buglife says the large garden bumblebee (Bombus ruderatus) is still found in Gloucestershire and Somerset, but over the past 50 years has disappeared from Dorset and the far South West.
The increased use of pesticides and unpredictable weather have contributed to their decline.
More top news
Adele described performing at Glastonbury as the "best moment" of her life as she took to the Pyramid Stage.
Luke Castiglione has the latest weather forecast. Cloudy with rain this afternoon, dry with plenty of sunshine tomorrow.
A man arrested on suspicion of murdering Melanie Hall 20 years ago has been released on police bail. She disappeared in Bath in 1996.