The British Beekeepers Association warned on Monday that the osmia avosetta could devastate already imperiled native populations either through spreading deadly viruses or by breeding and eventually out-competing other bees.
But Tim Lovett, a renowned expert and former president of the organisation, said it was highly unlikely one animal would cause a problem, particularly as the chances of it cross-breeding are very small.
The Toy family believe the bee inadvertently hitched a ride back to the UK after finding its way into one of their suitcases.
It prompted APHA to advise all travelers returning to the UK to check their bags thoroughly, especially if they have been left outside.
A solitary species of mason bee, found only in Turkey and Iran, osmia avosetta is unique in its use of flower petals to build nests in the ground in which its larvae can grow.
Officials have become acutely sensitive to the presence of foreign bees since invasions of predatory Asian hornets began in 2004.
Asked for her views on the government’s decision to kill the bee, Ms Toy said: “I know since they said it could possibly harm other bees that it had to be done, as harsh as it sounds.”