The bees like fresh, high-quality pollen
Details of how scientists plan to bring the extinct short-haired bumblebee back to the UK have been revealed.
The bee had survived in New Zealand after being shipped there by scientists in 1875 to establish a colony.
The move is possible after experts found that the secret to successful captive breeding of the insect lies in knowing what it likes to eat.
Nikki Gammans, project officer for the scheme, said: "The short-haired bumblebee is a very fussy eater."
"It needs fresh pollen every day, and not just any old pollen. It needs high quality pollen that has been collected by other bumblebees," she said.
Dr Gammans travelled to the Czech Republic to learn the technique from bee enthusiast Jaromir Cizek, who developed the method. She will now use it in New Zealand.
There she will use captive colonies of bumblebees to collect pollen, which is much more protein-rich than pollen collected by honeybees.
The team will brush this off the creatures' legs when they return, then feed it to the short-haired bumblebees.
Dr Gammans will travel to New Zealand's South Island in November, where she will spend four to eight weeks trying to capture as many queens as possible as they emerge from hibernation.
These will then be bred in captivity and the next generation, due to emerge in January and February next year, will be kept in hibernation and flown back to the UK to be released.
Dr Gammans said: "New Zealand is about to begin a programme to control Viper's bugloss because it's a non-native plant, but the short-haired bumblebees depend on it, so this is a now-or-never chance to rescue some of these bumblebees.
"If we're successful, this will be the first time a species has been reintroduced to the UK by bringing back direct descendants of the extinct population."
It is aimed the bees will eventually be released at Dungeness, Kent, where they were last seen.
They will be flown back on planes in cool boxes, and will not be disturbed, according to Natural England, as they will be in hibernation during transit.
The partnership project is being run by Natural England, the Bumblebee Conservation Trust the RSPB and Hymettus.