Harold Oldroyd (24 December 1913 – 3 September 1978) was a British entomologist. He specialised in the biology of flies, and wrote many books, especially popular science that helped entomology to reach a broader public. His The Natural History of Flies is considered to be the "fly Bible". Although his speciality was the Diptera, he acknowledged that they are not a popular topic: "Breeding in dung, carrion, sewage and even living flesh, flies are a subject of disgust...not to be discussed in polite society". It was Oldroyd who proposed the idea of hyphenating the names of true flies (Diptera) to distinguish them from other insects with "fly" in their names. Thus, the "house-fly", "crane-fly" and "blow-fly" would be true flies, while the "dragonfly", "scorpion fly" and so on belong to other orders. He also debunked the calculation that a single pair of house-flies, if allowed to reproduce without inhibitions could, within nine months, number 5.6×1012 individuals, enough to cover the Earth to a thickness of 14.3 m (47 ft). Oldroyd calculated that such a layer would only cover Germany, but remarked "that is still a lot of flies". All the following lists are potentially incomplete. Please add to them if you know of more. Papers by Oldroyd Cookson H. A., and Oldroyd H. 1937: Intestinal infestation by larvae of a drone fly. Lancet 2: 804. Oldroyd, H. 1940: The genus Hoplistomerus Macquart (Diptera: Asilidae). 5 figs., 12 pp. Trans. R. ent. Soc. Lond. Oldroyd, H. 1947a: Results of Armstrong College expedition to Siwa Oasis (Libyan desert), 1935. - Bulletin de la Société Fouad Ier d'Entomologie 31: 113-120, Kairo. Oldroyd, H. 1947b: The Diptera of the Territory of New Guinea. XIV. Family Tabanidae. Part II. Pangoniinae, except the genus Chrysops. Proc. Linn. Soc. N.S.W. 72: 125-42. Oldroyd, H. 1949a. A wingless empid (Diptera) from Tasmania. Entomol. Mon. Mag. 84: 278-79. Oldroyd, H. 1949b. The Diptera of the Territory of New Guinea. XIV. Family Tabanidae. Part III. Tabaninae. Proc. Linn. Soc. N.S.W. 73: 304-61. Oldroyd, H. 1952: A new Chrysops (Diptera, Tabanidae) from the British Cameroons. Ann Trop Med Parasitol. 1952 Sep;46(2):155-7. Oldroyd, H. 1952. The horseflies (Diptera: Tabanidae) of the Ethiopian Region. Volume I. Haematopota and Hippocentrum. British Museum (Natural History), London. ix + 226 pp. Oldroyd, H. 1954. The horseflies (Diptera: Tabanidae) of the Ethiopian Region. Volume II. Tabanus and related genera. British Museum (Natural History), London. x + 341