Isidore of Seville [7th century CE] (Etymologies, Book 12, 5:12; 12, 5.15; 12, 5.18): [Book 12, 5.12] There are flesh vermin [such as] the tarmus... [Book 12, 5.15] The tarmus is a vermin found in fat. [Book 12, 5.18]...vermin are generated in putrid meat ... the tarmus in fat. - [Barney, Lewis, et. al. translation]

Thomas of Cantimpré [circa 1200-1272 CE] (Liber de natura rerum, Worms 9.50): Tarmus is a worm, as Isidore says, from which it has its name. [Thomas here has mistakenly added Isidore's account of the uria (a worm that raises blisters) to the tarmus. Uria immediately follows tarmus in Isidore (Book 12, 5.16).] For where it bites, the place burns so much that blisters rise, and this worm is born in lard. But we call lard [lardum] the fat of the pig which is immediately under the skin, between the skin and the red flesh; and it is a name taken from the French language. - [Badke translation/paraphrase]