A survey is being run to find out why bumble-bees are disappearing.
The survey aims to find out how reliant the insects are on gardens
Durham Wildlife Trust is starting the project after surveys showed a steady decline in bumble-bee species, distribution and numbers across the UK.
It hopes to recruit members of the public to join the survey to help save the endangered insects.
The trust says possible reasons for the decline include change in climate and agricultural practices.
It says in its area, which includes County Durham, Sunderland, South Tyneside, Gateshead and Darlington, the insect is disappearing from many of its old haunts and is becoming more dependent on flower-rich parks and gardens.
Trust conservation manager Terry Coult said: "I am old enough to remember when, on summer days, bumble-bees could be found on every road side verge and in most fields, along with grasshoppers - another insect group rapidly disappearing from our tidied and over-managed countryside.
"From a possible 18 bumble-bee species which were once found in County Durham, about six can still be found commonly in gardens with a few specialists still surviving in the wilder countryside."
The survey aims to find out how reliant bumble-bees are on gardens, where they are in the country and try to measure the numbers in gardens compared to the open countryside.
The survey will concentrate on the red tailed bumble-bee, which has a red tip on its abdomen, and the common carder bee.