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".
The Asilidae are the robber fly family, also called assassin flies. They are powerfully built, bristly flies with a short, stout proboscis enclosing the sharp, sucking hypopharynx. The name "robber flies" reflects their expert predatory habits; they feed mainly or exclusively on other insects and, as a rule, they wait in ambush and catch their prey in flight.
The Therevidae are a family of flies of the superfamily Asiloidea commonly known as stiletto flies. The family contains about 1,600 described species worldwide, most diverse in arid and semiarid regions with sandy soils. The larvae are predators of insect larvae in soil.
Rhagionidae or snipe flies are a small family of flies. They get their name from the similarity of their often prominent proboscis that looks like the beak of a snipe.
Pegesimallus is a genus of robber flies.
Laphriinae is a subfamily of robber flies in the family Asilidae. There are more than 110 genera and 1,000 described species in Laphriinae. Many are mimics of syntopic bees. Some prey on bees as adults. Larvae of the genus Hyperechia are known to grow inside the cells of Xylocopa bees, feeding on their larvae.
Diogmites is a genus of mainly neotropical flies in the family Asilidae or robber flies.
Neoitamus melanopogon, commonly known by the name common robber fly, is a species of fly of Asilidae in the genus Neoitamus, found in both the principal islands of New Zealand.
Metadioctria is a genus of robber flies in the family Asilidae. There are at least three described species in Metadioctria.
Cerotainiops is a genus of robber flies in the family Asilidae. There are about six described species in the genus Cerotainiops.
Diogmites missouriensis is a species of robber flies in the family Asilidae.
Eudioctria is a genus of robber flies in the family Asilidae. There are about 14 described species in Eudioctria.
Cyrtopogon is a genus of robber flies in the family Asilidae. There are at least 120 described species in Cyrtopogon.
Neomochtherus is a genus of robber flies in the family Asilidae. There are at least 140 described species in Neomochtherus.
Callinicus is a genus of robber flies in the family Asilidae. There are about five described species in Callinicus.
Diogmites texanus is a species of robber flies in the family Asilidae.
Choerades marginata is a species of robber fly found in Europe.
Mallophora ruficauda is a species of parasitic robber fly in the family Asilidae, endemic to South and Central America. Like other robber flies, M. ruficauda is known for its aggressive behavior and predation upon other insects, especially bees. M. ruficauda mimics a bumblebee to fool predators into thinking it has a painful sting and is not worth eating.
Hyperechia is a genus of robber flies in the family Asilidae. They appear large, stout and with legs covered in bristles and appear like carpenter bees in the genus Xylocopa and the resemblance is considered as a case of aggressive mimicry, providing protection from predators. The larvae of the fly feed on the larvae of Xylocopa within their cavity nests in wood. They are mainly found in the African and Madagascan region with about 15 species and two species in Asia.
Trichoura is a genus of robber flies in the family Asilidae discovered by Londt in 1994. There are 7 described species in Trichoura. Species in this genus live in tropical biomes across the African continent.
Female with butterfly prey
Alcimus with grasshopper prey
Male Alcimus with female Alcimus prey
