Hoverfly

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Syrphidae
Temporal range: Eocene–Present
Syrphidae poster.jpg
Sixteen different species of hoverflies
Scientific classification Red Pencil Icon.png
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Diptera
Section: Aschiza
Superfamily: Syrphoidea
Family: Syrphidae
Latreille, 1802
Subfamilies

Hoverflies, also 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.

Contents

Insects such as aphids are considered a crop pest, and therefore the aphid-eating larvae of some hover flies serve as an economically (as well as ecologically) important predator and even potential agents for use in biological control, while the adults may be 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 mammals, though many species are mimics of stinging wasps and bees, a mimicry which may serve to ward off predators.

Description


The size of hoverflies varies depending on the species. [1] Some, such as members of the genus Baccha , are small, elongated, and slender, while others, such as members of Criorhina , are large, hairy, and yellow and black. As members of the Diptera, all hoverflies have a single functional pair of wings (the hind wings are reduced to balancing organs). [2] Many species 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 to humans. [1] Drone flies, E. tenax, are an example of a species of hoverfly who exhibit Batesian mimicry.

With a few exceptions, [3] hoverflies are distinguished from other flies by having a spurious vein, located parallel to their fourth longitudinal wing vein. [1] Adults feed mainly on nectar and pollen. [2] Many species also hover around flowers, lending to their common name. [1]

Bee flies of the family Bombyliidae often mimic Hymenoptera and hover around flowers, as well, rendering some bombyliid species hard to tell apart from Syrphidae at first glance. Hoverflies can, nevertheless, be distinguished in the field by anatomical features such as:

Reproduction and life cycle

Midair mating of Simosyrphus grandicornis Hoverflies mating midair.jpg
Midair mating of Simosyrphus grandicornis

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] [4] Predatory species are beneficial to farmers and gardeners, as aphids destroy crops, and hoverfly maggots are often used in biological control. This includes one of the most common widespread hoverfly species, Syritta pipiens , whose larvae feed on aphids. Certain species, such as Lampetia equestris or Eumerus tuberculatus , are responsible for pollination.

Hoverfly depositing egg on Epipactis helleborine which has ants farming aphids Hoverfly depositing egg.jpg
Hoverfly depositing egg on Epipactis helleborine which has ants farming aphids

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. [5] The maggots also have a commercial use, and are sometimes sold for ice fishing. [6]

An ichneumonid wasp ovipositing inside a hoverfly larva Parasitoid wasp oviposits inside hoverfly larva.jpg
An ichneumonid wasp ovipositing inside a hoverfly larva

On extremely rare occasions, hoverfly larvae have been known to cause accidental myiasis in humans. This occurs when the larvae are accidentally ingested from contaminated food. [5] [7]

Evolution

The oldest known fossils of crown group Syrphidae are from the Eocene aged Florissant Formation, Green River Formation and Baltic amber. However, the genus Prosyrphus from the Late Cretaceous (Cenomanian) aged Burmese amber appears to represent a stem group to the family. [8]

Distribution and habitat

Hoverflies are a cosmopolitan family found in most biomes, except extreme deserts, tundra at extremely high latitudes, and Antarctica. [9] [10] Certain species are more common in certain areas than others; for example, the American hoverfly, Eupeodes americanus, is common in the Nearctic realm, and the common hoverfly, Melangyna viridiceps, is common in the Australasian realm. About 6,000 species and 200 genera are in the family. [11]

While some hoverfly larvae are aquatic and are often found in stagnant water, those of species that prey upon aphids and other plant parasites are usually terrestrial, residing on leaves. [12] Adults are often found near flowers, 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.

Pollination

Episyrphus balteatus on a daisy Hoverfly October 2007-21.jpg
Episyrphus balteatus on a daisy
Eupeodes corollae ComputerHotline - Syrphidae sp. (by) (3).jpg
Eupeodes corollae

Hoverflies are important pollinators of flowering plants in many ecosystems worldwide. [13] Syrphid flies are frequent flower visitors to a wide range of wild plants, as well as agricultural crops, and are often considered the second-most important group of pollinators after wild bees. However, relatively little research into fly pollinators has been conducted compared with bee species. [13] Bees are thought to be able to carry a greater volume of pollen on their bodies, but flies may be able to compensate for this by making a greater number of flower visits.

Like many pollinator groups, syrphid flies range from species that take a generalist approach to foraging by visiting a wide range of plant species through those that specialize in a narrow range of plants. [14] Although hoverflies are often considered mainly nonselective pollinators, some hoverflies species are highly selective and carry pollen from one plant species. [15] Cheilosia albitarsis is thought to only visit Ranunculus repens.

Specific flower preferences differ among species, but syrphid fly species have repeatedly been shown to prefer white- and yellow-coloured flowers. [16] Nonvisual flower cues such as olfactory cues also help these flies to find flowers, especially those that are not yellow. [17] Many syrphid fly species have short, unspecialized mouth parts and tend to feed on flowers that are more open as the nectar and pollen can be easily accessed. [18]

Also, a number of fascinating interactions occur between orchids and hoverflies. The orchid species Epipactis veratrifolia mimics alarm pheromones of aphids which attracts pollinating hoverflies . [19] Another plant, the slipper orchid in southwest China, also achieves pollination by deceit by exploiting the innate yellow color preference of syrphids. [20]

Case study – New Zealand

More than 40 species of syrphid flies are found in New Zealand [21] in a variety of habitats, including agricultural fields and alpine zones. Two hoverfly species in Switzerland are being investigated as potential biological control agents of hawkweeds in New Zealand. [22]

Native hoverfly species Melanostoma fasciatum and Melangyna novaezelandiae are common on agricultural fields in New Zealand. [23] Coriander and tansy leaf are particularly attractive to many species of adults, which feed on their pollen. [24] In organic paddocks, hoverflies were found to feed on an average of three and a maximum of six different pollens. M. fasciatum has a short proboscis, which restricts it to obtaining nectar from disk flowers. [25]

Syrphid flies are also common visitors to flowers in alpine zones in New Zealand. Native flies ( Allograpta and Platycheirus ) in alpine zones show preferences for flower species based on their colour in alpine zones; syrphid flies consistently choose yellow flowers over white regardless of species. [26] However, syrphid flies are not as effective pollinators of alpine herb species as native solitary bees. [27]

Systematics

Relationship with humans

Larvae of many hoverfly species prey upon pest insects, including aphids and leafhoppers, which spread some diseases such as curly top, so they are seen in biocontrol as a natural means of reducing the levels of pests. Gardeners, therefore, sometimes use companion plants to attract hoverflies. Those reputed to do so include Alyssum spp., Iberis umbellata , statice, buckwheat, chamomile, parsley, and yarrow.

Fredrik Sjöberg's  [ sv ] book The Fly Trap concerns his enthusiasm for hoverflies on the island of Runmarö in the Baltic Sea. [28] The island is a hotspot for hoverflies and other insects; Sjöberg has collected 58 species of butterflies there, and (in seven years of hunting) 202 species of hoverflies, including 180 in his garden. [29]

Identification guides

Regional lists

Related Research Articles

Fly Order of insects

Flies are insects of the order Diptera, the name being derived from the Greek δι- di- "two", and πτερόν pteron "wing". Insects of this order use only a single pair of wings to fly, the hindwings having evolved into advanced mechanosensory organs known as halteres, which act as high-speed sensors of rotational movement and allow dipterans to perform advanced aerobatics. Diptera is a large order containing an estimated 1,000,000 species including horse-flies, crane flies, hoverflies and others, although only about 125,000 species have been described.

Pollinator Animal that moves pollen from the male anther of a flower to the female stigma of a flower

A pollinator is an animal that moves pollen from the male anther of a flower to the female stigma of a flower. This helps to bring about fertilization of the ovules in the flower by the male gametes from the pollen grains.

Bombyliidae Family of flies

The Bombyliidae are a family of flies. Their common name are bee flies or humbleflies. Adults generally feed on nectar and pollen, some being important pollinators. Larvae generally are parasitoids of other insects.

Entomophily Form of pollination by insects

Entomophily or insect pollination is a form of pollination whereby pollen of plants, especially but not only of flowering plants, is distributed by insects. Flowers pollinated by insects typically advertise themselves with bright colours, sometimes with conspicuous patterns leading to rewards of pollen and nectar; they may also have an attractive scent which in some cases mimics insect pheromones. Insect pollinators such as bees have adaptations for their role, such as lapping or sucking mouthparts to take in nectar, and in some species also pollen baskets on their hind legs. This required the coevolution of insects and flowering plants in the development of pollination behaviour by the insects and pollination mechanisms by the flowers, benefiting both groups.

Zoophily

Zoophily is a form of pollination whereby pollen is transferred by animals, usually by invertebrates but in some cases vertebrates, particularly birds and bats, but also by other animals. Zoophilous species frequently have evolved mechanisms to make themselves more appealing to the particular type of pollinator, e.g. brightly colored or scented flowers, nectar, and appealing shapes and patterns. These plant-animal relationships are often mutually beneficial because of the food source provided in exchange for pollination.

<i>Eristalis tenax</i> Species of fly

Eristalis tenax, the common drone fly, is a common, migratory, cosmopolitan species of hover fly. It is the most widely distributed syrphid species in the world, and is known from all regions except the Antarctic. It has been introduced into North America and is widely established. It can be found in gardens and fields in Europe and Australia. It has also been found in the Himalayas.

<i>Rhingia campestris</i> Species of fly

Rhingia campestris is a species of hoverfly, 7–11 millimetres (0.3–0.4 in) long, with a wingspan of 12–18 mm (0.5–0.7 in). It is common across the Palearctic from March until November. It has a broad orange abdomen with a black line along the sides, and has the distinctive long snout of all Rhingia species. Rhingia campestris is the main pollinator for many plant species and due to its long snout it can forage on tubulous flowers. Larvae are associated with cow dung. Adults males feed on nectar, while adult females feed on protein rich pollen, reflecting the cost of developing eggs.

<i>Melangyna viridiceps</i> Species of fly

Melangyna viridiceps is an Australian hoverfly, known as the common hover fly.

<i>Bombylius major</i> Species of fly

Bombylius major is a parasitic bee mimic fly. B. major is the most common type of fly within the Bombylius genus. The fly derives its name from its close resemblance to bumblebees and are often mistaken for them.

Eristalinae Subfamily of flies

Eristalinae are one of the four subfamilies of the fly family Syrphidae, or hoverflies. A well-known species included in this subfamily is the dronefly, Eristalis tenax.

<i>Syritta pipiens</i> Species of fly

Syritta pipiens, sometimes called the thick-legged hoverfly, is one of the most common species in the insect family Syrphidae. This fly originates from Europe and is currently distributed across Eurasia and North America. They are fast and nimble fliers, and their larvae are found in wet, rotting organic matter such as garden compost, manure, and silage. The species is also commonly found in human-created environments such as most farmland, gardens, and urban parks, wherever there are flowers. This species is an important part of its native ecosystem as adult Syritta pipiens flies are critical pollinators for a variety of flowering plants and the species supports parasitism by various parasitic wasp species. Thus, they play an important role in environmental functionality, and can serve as bio-indicators, in which their abundance can reflect the health of the environment. They can also serve as a biological control agent against pests such as lettuce aphids.

<i>Merodon equestris</i> Species of fly

Merodon equestris is a Holarctic species of hoverfly. Like many other hoverflies it displays a colouration pattern similar to a stinging insect as an evolutionary defense mechanism. Other syrphid bee mimics are Mallota, Arctophila, Criorhina, Pocota and Brachypalpus. Merodon species are distinguished from these by the very strong hind femora, which bear a large triangular projection on the underside near the tip. It flies in low vegetation while the other bumblebee mimics prefer higher vegetation layers.

<i>Toxomerus</i> Genus of flies

Toxomerus is a very large genus of hoverflies. They are found in many parts of North and South America. Most larvae are predators on soft bodied insects, though a few species have been shown to feed on pollen. Adults feed on the pollen of a wide range of flowers.

<i>Syrphus torvus</i> Species of insect

Syrphus torvus is a common species of hoverfly found in the Holarctic. The adults feed on pollen and nectar, but the larvae feed on aphids.

<i>Parasyrphus nigritarsis</i> Species of fly

Parasyrphus nigritarsis is a species of hoverfly, from the family Syrphidae, in the order Diptera. It is known from northern Europe and North America, and has been considered to be a rare species in parts of its range. Adults visit flowers as a source of nutrition, and females lay their eggs on clutches of eggs of leaf beetles. When the Parasyrphus larvae hatch, they first consume leaf beetle eggs and then consume immature beetles until they reach the pupal stage. This species is related to hoverflies that prey on aphids as larvae, and has been investigated in studies of chemical ecology and food web ecology.

Diptera is an order of winged insects commonly known as flies. Diptera, which are one of the most successful groups of organisms on Earth, are very diverse biologically. None are truly marine but they occupy virtually every terrestrial niche. Many have co-evolved in association with plants and animals. The Diptera are a very significant group in the decomposition and degeneration of plant and animal matter, are instrumental in the breakdown and release of nutrients back into the soil, and whose larvae supplement the diet of higher agrarian organisms. They are also an important component in food chains.

<i>Melangyna novaezelandiae</i> Species of fly

Melangyna novaezelandiae is a hoverfly endemic to New Zealand. It is a generalized pollinator of a large range of plants that are both native and exotic to the New Zealand flora. M. novaezelandiae is widespread throughout New Zealand, including in agricultural environments. The larvae of this species feeds on other arthropods and may have uses as a biocontrol agent.

Among the pollinating insects of New Zealand are numerous species of the Syrphidae or hoverfly family.

Melanostoma fasciatum is a species of hoverfly found in New Zealand, where it is common in agricultural fields and gardens. Locally dense populations of this hoverfly species might effectively reduce pest infestation. Hence, they are perhaps an effective natural and non-toxic bioagent that may control and reduce aphid and small caterpillar populations.

<i>Spilomyia longicornis</i> Species of fly

Spilomyia longicornis is a species of syrphid fly, also known as a flower fly or hoverfly, in the family Syrphidae. Although the appearance of S. longicornis is remarkably similar to a vespid wasp, it is a fly and cannot sting. It occurs in North America, east of the Rocky Mountains.

References

  1. 1 2 3 4 5 6 7 "Hover fly". Encyclopædia Britannica Online. 2009. Retrieved December 5, 2009.
  2. 1 2 3 4 "Hoverfly". Hutchinson Encyclopedia. Helicon Publishing. 2009. Retrieved December 6, 2009.
  3. Reemer, Menno (2008). "Surimyia, a new genus of Microdontinae, with notes on Paragodon Thompson, 1969 (Diptera, Syrphidae)" (PDF). Zoologische Mededelingen . 82: 177–188.
  4. Schmidt, Martin; Thewes, Ulrich; Thies, Carsten; Tscharntke, Teja (2004). "Aphid suppression in mulched cereals". Entomologia Experimentalis et Applicata. 113 (2): 87–93. doi:10.1111/j.0013-8703.2004.00205.x. S2CID   85070615.
  5. 1 2 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. doi:10.1128/JCM.37.9.3082-3082.1999. PMC   85471 . PMID   10475752.
  6. Dictionary of Ichthyology; Brian W. Coad and Don E. McAllister Archived 2009-12-06 at the Wayback Machine at ww.briancoad.com
  7. Whish-Wilson PB (2000). "A possible case of intestinal myiasis due to Eristalis tenax". The Medical Journal of Australia . 173 (11–12): 652. doi:10.5694/j.1326-5377.2000.tb139374.x. PMID   11379520. S2CID   12898612.
  8. Grimaldi, David A. (2018-10-24). "Basal Cyclorrhapha in amber from the Cretaceous and Tertiary (Insecta: Diptera), and their relationships: Brachycera in Cretaceous amber Part IX". Bulletin of the American Museum of Natural History. 423 (423): 1–97. doi:10.1206/0003-0090-423.1.1. ISSN   0003-0090. S2CID   91679754.
  9. Barkemeyer, Werner. "Syrphidae (hoverflies)". Biodiversity Explorer. South Africa: Iziko Museum . Retrieved December 11, 2009.
  10. Thompson, F. Christian (August 19, 1999). "Flower Flies". The Diptera Site. United States Department of Agriculture. Archived from the original on December 11, 2009. Retrieved December 11, 2009.
  11. Philip J. Scholl; E. Paul Catts; Gary R. Mullen (2009). "Myiasis (Muscoidea, Oestroidea)". In Gary Mullen; Gary Richard Mullen; Lance Durden (eds.). Medical and Veterinary Entomology (2nd ed.). Academic Press. pp. 309–338. ISBN   978-0-12-372500-4.
  12. Laura Smith. "Syrphidae, hover flies". bumblebee.org.
  13. 1 2 Larson, B.M.H; Kevan, P.G.; Inouye, D. W. (2001). "Flies and flowers: taxonomic diversity of anthophiles and pollinators". Canadian Entomologist. 133 (4): 439–465. doi:10.4039/ent133439-4. S2CID   55767580.
  14. Van Der Kooi, C. J.; Pen, I.; Staal, M.; Stavenga, D. G.; Elzenga, J. T. M. (2015). "Competition for pollinators and intra-communal spectral dissimilarity of flowers". Plant Biology. 18 (1): 56–62. doi:10.1111/plb.12328. PMID   25754608.
  15. Haslett, J.R. (1989). "Interpreting patterns of resource utilization: randomness and selectivity in pollen feeding by adult hoverflies". Oecologia. 78 (4): 433–442. doi:10.1007/bf00378732. PMID   28312171. S2CID   9178645.
  16. Sajjad, Asif; Saeed, Shafqat (2010). "Floral host plant range of syrphid flies (Syrphidae: Diptera) under natural conditions in southern punjab, Pakistan". Pakistan Journal of Biology. 42 (2): 1187–1200.
  17. Primante, Clara; Dotterl, Stefan (2010). "A syrphid fly uses olfactory cues to find a non-yellow flower". Journal of Chemical Ecology. 36 (11): 1207–1210. doi:10.1007/s10886-010-9871-6. PMID   20924654. S2CID   23245484.
  18. Campbell, Alistair, J.; Biesmeijer, J. C.; Varma, V.; Wakers, F. L. (2012). "Realising multiple ecosystem services based on the response of three beneficial insect groups to floral traits and trait diversity". Basic and Applied Ecology. 13 (4): 363–370. doi:10.1016/j.baae.2012.04.003.
  19. Stokl, Johannes; Brodmann; Dafni; Ayasse; Hansson (2011). "Smells like aphids: orchid flowers mimic aphid alarm pheromones to attract hoverflies for pollination". Proc. R. Soc. B. 278 (1709): 1216–1222. doi:10.1098/rspb.2010.1770. PMC   3049078 . PMID   20943694.
  20. Shi, J.; Luo, Y.B.; Ran, J.C.; Liu, Z.J.; Zhou, Q. (2009). "Pollination by deceit in Paphiopedilum barbigerum (Orchidaceae): a staminode exploits innate colour preferences of hoverflies (Syrphidae)". Plant Biology. 11 (1): 17–28. doi:10.1111/j.1438-8677.2008.00120.x. PMID   19121110.
  21. "Diptera: Syrphidae". Landcare Research. Retrieved 2013-08-30.
  22. Grosskopf, Gitta (2005). "Biology and life history of Cheliosia urbana (Meigen) and Cheilosia psilophthalma (Becker), two sympatric hoverflies approved for the biological control of hawkweeds (Hieracium spp.) in New Zealand". Biological Control. 35 (2): 142–154. doi:10.1016/j.biocontrol.2005.06.013.
  23. Morris, Michael, C. (2000). "Coriander (Coriandrum sativum) "companion plants" can attract hover flies, and may reduce infestation in cabbages". New Zealand Journal of Crop and Horticultural Science. 28: 213–217. doi:10.1080/01140671.2000.9514141. S2CID   86656803.
  24. Hickman, Janice, M.; Lovei, G. L.; Wratten, S. D. (1995). "Pollen feeding by adults of the hoverfly Melanostoma fasciatum (Diptera: Syrphidae)". New Zealand Journal of Zoology. 22 (4): 387–392. doi:10.1080/03014223.1995.9518057.
  25. Holloway, Beverley, A. (1976). "Pollen-feeding in hover-flies (Diptera:Syrphidae)". New Zealand Journal of Ecology. 3 (4): 339–350. doi:10.1080/03014223.1976.9517924.
  26. Campbell, Diane; Bischoff, M.; Lord, J. M.; Robertson, A. W. (2010). "Flower color influences insect visitation in alpine New Zealand". Ecology. 91 (9): 2638–2649. doi:10.1890/09-0941.1. PMID   20957958. S2CID   473295.
  27. Bischoff, Mascha; Campbell, D. R.; Lord, J. M.; Robertson, A. W. (2013). "The relative importance of solitary bees and syrphid flies as pollinators of two outcrossing plant species in the New Zealand alpine". Austral Ecology. 38 (2): 169–176. doi:10.1111/j.1442-9993.2012.02389.x.
  28. Sjöberg, Fredrik (2014). The Fly Trap. Particular Books. p. 197. ISBN   978-1-84614-776-0.
  29. Barkham, Patrick (14 June 2014). "Fredrik Sjöberg: 'I realised I had to write my book for people not interested in flies'". The Guardian. Retrieved 15 March 2015.

Species lists