Vespiform
Vespiforms were an insectoid race which had hives in the Silfrax Galaxy. (DW: The Unicorn and the Wasp)
Biology
Vespiforms were a species of insectoids which resembled oversized (nearly three metres long) wasps. They had the ability to transform into the guise of other species, even to the extent of near-Humans. The tranformations were accompanied by a glowing, purple-pink haze and left behind morphic residue. When in another form, Vespiforms were genetically compatable with the mimicked species - they were even able to breed with members of the species. (DW: The Unicorn and the Wasp)
Vespiforms also had telepathic recorders, an essential part of their mind which could record motivations for them. One such recorder, the Firestone, ended up in the hands of Clemency Eddison in 1885. (DW: The Unicorn and the Wasp)
History
At some point in their history in the 19th century or prior, the Vespiforms developed space travel.
In 1885, a Vespiform (simply known as Christopher) arrived on Earth and had a child with Clemency Eddison. He drowned in the monsoon of that year. The child was sent to be adopted and eventually became a reverend, Arnold Golightly. At the age of 40 in 1926, he had discovered his Vespiform nature. Because of the influence of Agatha Christie's novels and the Firestone, Golightly started commiting various murders before Agatha Christie controlled him to end up near a lake. Donna Noble arrived with the Doctor and threw the Firestone into the lake. Golightly (in Vespiform form) followed and drowned, but relieved Agatha of his connection with her in his dying moment. (DW: The Unicorn and the Wasp)
According to the Torchwood Institute, the Vespiforms may have gone to war with Quark rebels, though they themselves doubted the accuracy of that information. (Captain Jack's Monster Files: Vespiform)
Technology
Vespiforms had their own intergalactic travel capabilities, allowing them to travel from their home galaxy to Mutter's Spiral.
Behind the Scenes
Torchwood's belief that the Vespiforms may have gone to war with the Quarks is probably a reference to a comic strip where Giant Wasps are working with the Quarks but then turn against them. This is in TVC: The Killer Wasps