|Sixteen different species of hoverfly|
Hoverflies, sometimes called flower flies or syrphid flies, make up the insect family Syrphidae. As their common name suggests, they are often seen hovering or nectaring at flowers; the adults of many species feed mainly on nectar and pollen, while the larvae (maggots) eat a wide range of foods. In some species, the larvae are saprotrophs, eating decaying plant and animal matter in the soil or in ponds and streams. In other species, the larvae are insectivores and prey on aphids, thrips, and other plant-sucking insects.
Aphids alone cause tens of millions of dollars of damage to crops worldwide every year; because of this, aphidophagous hoverflies are being recognized as important natural enemies of pests, and potential agents for use in biological control. Some adult syrphid flies are important pollinators.
About 6,000 species in 200 genera have been described. Hoverflies are common throughout the world and can be found on all continents except Antarctica. Hoverflies are harmless to most other animals despite their mimicry of more dangerous wasps and bees, which serves to ward off predators.
The size of hoverflies varies, depending on the species.1 Some, like members of the genus Baccha, are small, elongate and slender, while others, like members of Criorhina are large, hairy, and yellow and black. As members of Diptera, all hoverflies have a single functional pair of wings (the hindwings are reduced to balancing organs).2 They are brightly colored, with spots, stripes, and bands of yellow or brown covering their bodies.2 Due to this coloring, they are often mistaken for wasps or bees; they exhibit Batesian mimicry. Despite this, hoverflies are harmless.1
With a few exceptions (e.g.3), hoverflies are distinguished from other flies by a spurious vein, located parallel to the fourth longitudinal wing vein.1 Adults feed mainly on nectar and pollen.2 They also hover around flowers, lending to their common name.1
Unlike adults, the maggots of hoverflies feed on a variety of foods; some are saprotrophs, eating decaying plant or animal matter, while others are insectivores, eating aphids, thrips, and other plant-sucking insects.1 This is beneficial to gardens, as aphids destroy crops, and hoverfly maggots are often used in biological control. Certain species, such as Lampetia equestris or Eumerus tuberculatus, are responsible for pollination.
An example of a well-known hoverfly maggot is the rat-tailed maggot, of the drone fly, Eristalis tenax. It has a breathing siphon at its rear end, giving it its name.1 The species lives in stagnant water, such as sewage and lagoons.4 The maggots also have a commercial use, and are sometimes sold for ice fishing.5
On occasion, Hoverfly larvae have been known to cause accidental myiasis in humans. This occurs when the larva are accidentally ingested on food or from other sources. Myiasis causes discomfort, pain, or itching,46 however, Hoverflies do not normally prey upon humans and cases of myiasis from Hoverflies is very rare.
Hoverflies are a cosmopolitan family found in most biomes, except deserts, tundra at extremely high latitudes, and Antarctica.78 Certain species are more common in certain areas than others; for example, the American hoverfly, Eupeodes americanus, is common in the Nearctic ecozone, and the common hoverfly, Melangyna viridiceps, is common in the Australasia ecozone. About 6,000 species and 200 genera are in the family.9
Larvae of hoverflies are often found in stagnant water. Adults are often found near plants, their principal food source being nectar and pollen.2 Some species are found in more unusual locations; for example, members of the genus Volucella can be found in bumblebee nests, while members of Microdon are myrmecophiles, found in ant or termite nests.1 Others can be found in decomposing vegetation.
See Genera of Syrphidae.
Many species of hoverfly larvae prey upon pest insects, including aphids and the leafhoppers, which spread some diseases such as curly top. Therefore, they are seen in biocontrol as a natural means of reducing the levels of pests.
- Stubbs, A.E. and Falk, S.J. (2002) British Hoverflies An Illustrated Identification Guide. Pub. 1983 with 469 pages, 12 col plates, b/w illus.British Entomological and Natural History Society ISBN 1-899935-05-3. 276 species are described with extensive keys to aid identification. 190 species are displayed on the colour plates. 2nd edition, pub. 2002, includes new British species and name changes. Also includes European species which are likely to be found in Britain. There are additional black & white plates illustrating the male genitalia of the difficult genera Cheilosia and Sphaerophoria.
- Vockeroth, J.R. A revision of the genera of the Syrphini (Diptera: Syrphidae) Memoirs of the Entomological Society of Canada, no. 62:1-176. Keys subfamilies, tribes and genera on a world basis and under regions.
- van Veen, M.P. |(2004) "Hoverflies of Northwest Europe, Identification Keys to the Syrphidae". KNNV Publishing, Utrecht. ISBN 9050111998
- List of hoverfly species of Great Britain
- List of New Zealand Flower Flies
- List of the Flower Flies of North America
- Episyrphus balteatus - marmalade fly (worldwide distribution)
- "Hover fly". Encyclopædia Britannica Online. 2009. Retrieved December 5, 2009.
- "Hoverfly". Hutchinson Encyclopedia. Helicon Publishing. 2009. Retrieved December 6, 2009.
- Reemer, Menno (2008). "Surimyia, a new genus of Microdontinae, with notes on Paragodon Thompson, 1969 (Diptera, Syrphidae)" (PDF). Zoologische Mededelingen 82: 177–188.
- Aguilera A, Cid A, Regueiro BJ, Prieto JM, Noya M (September 1999). "Intestinal myiasis caused by Eristalis tenax". Journal of Clinical Microbiology 37 (9): 3082. PMC 85471. PMID 10475752.
- Dictionary of Ichthyology; Brian W. Coad and Don E. McAllister at ww.briancoad.com
- Whish-Wilson PB (2000). "A possible case of intestinal myiasis due to Eristalis tenax". The Medical Journal of Australia 173 (11–12): 652. PMID 11379520.
- Barkemeyer, Werner. "Syrphidae (hoverflies)". Biodiversity Explorer. South Africa: Iziko Museum. Retrieved December 11, 2009.
- Thompson, F. Christian (August 19, 1999). "Flower Flies". The Diptera Site. United States Department of Agriculture. Retrieved December 11, 2009.
- Philip J. Scholl, E. Paul Catts & Gary R. Mullen (2009). "Myiasis (Muscoidea, Oestroidea)". In Gary Mullen, Gary Richard Mullen & Lance Durden. Medical and Veterinary Entomology (2nd ed.). Academic Press. pp. 309–338. ISBN 978-0-12-372500-4.
|Wikimedia Commons has media related to: Syrphidae|
|Wikispecies has information related to: Syrphidae|
- Hoverfly - index to scholarly articles
- A web-site about Dutch hoverflies
- All About Hoverflies
- Hoverfly Recording Scheme - UK Dipterists Forum
- Syrphidae species in Europe and Africa, with photos, range maps, checklists and literature
- Large numbers of Syrphidae photos
- Northwest Europe Hoverflies - archived at The Wayback Machine
- Photographs of World Hoverflies from Japan, in English
- Diptera.info Picture Gallery
- "A hover fly, Allograpta obliqua". Featured Creatures. University of Florida / Institute of Food and Agricultural Sciences.