Melissa Majoria was the homeworld of Migrant Bees, some of which made their way to Earth. By 2009, the bees sensed that a catastrophe was about to befall the Earth, and began to make their way back to Melissa Majoria. (TV: The Stolen Earth [+]Russell T Davies, Doctor Who series 4 (BBC One, 2008).) Donna Noble noticed this, and remarked it to the Tenth Doctor several times. He also found it odd. (TV: Partners in Crime [+]Russell T Davies, Doctor Who series 4 (BBC One, 2008)., Planet of the Ood [+]Keith Temple, Doctor Who series 4 (BBC One, 2008).)
The catastrophe was Davros moving the Earth to the Medusa Cascade. The bees' movement created a disturbance on the Tandocca Scale, which allowed the Doctor and Donna to trace their path towards the Earth. (TV: The Stolen Earth [+]Russell T Davies, Doctor Who series 4 (BBC One, 2008).)
Behind the scenes[]
The phenomenon of bees disappearing is a real-life concern which has garnered some fair media attention. Additionally, the name "Melissa" comes from the Greek word for "bee."