Eristalis tenax

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Eristalis tenax
Eristalis 2007-1.jpg
Male
Hoverfly (Eristalis tenax) female.jpg
Female
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Diptera
Family: Syrphidae
Genus: Eristalis
Species:
E. tenax
Binomial name
Eristalis tenax
Synonyms [1]
  • Eristalis campestris Meigen, 1822
  • Musca tenaxLinnaeus, 1758

Eristalis tenax, the common drone fly, is a common, migratory, cosmopolitan species of hover fly. [2] 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 [3] and Australia. [4] It has also been found in the Himalayas. [5]

Contents

Distribution

The larval form of the drone-fly, the rat-tailed maggot, is found on every continent except Antarctica, and ranges to the highest latitudes in the North. [6] This species is not prevalent in extremely southern latitudes, neither is it common in arid areas of Europe, Asia, and Africa. [6] In the United States, this species is found as far north as Alaska and as far south as California and Florida. [6]

Drone fly on meadow salsify (Tragopogon pratensis) Eristalis tenax auf Tragopogon pratensis 01.JPG
Drone fly on meadow salsify ( Tragopogon pratensis )

Description

Eristalis tenax is a large, stocky bee mimic. The eyes are marbled in black. Males have hovering displays. The average wing length is 9.75–13 mm and their average wingspan is 15 mm.

The exact appearance of the drone fly can vary considerably. [7] The abdomen can vary in color from dark brown to orange. [7] Pigmentation has an important role in the control of body temperature; the black areas down the center of the drone-flies abdomen may absorb solar radiation and so warm the dorsal blood vessel, which is right underneath. [7]

Territoriality

Males of E. tenax can be strongly territorial in the summer, guarding territories such as flowerbeds or bushes to ensure a chance to mate. The males hover motionless in the air and dart after intruders to chase them out of the territory. [8]

Research suggest that male drone flies live in the same territory their entire lives. [6] They mate, feed, and groom in this area, and they defend the area against other insects. [6] When male E. tenax of the spring and summer generations stop dispersing, they settle within home ranges which provide them with locations suitable for sheltering, resting, basking, grooming, feeding and mating. [9] When away from its "home territory", a male drone fly rarely responds to other insects. [9] But when it is on its mating site, the male is very territorial, attacking alien species such as bees, wasps, and butterflies. [9] Being on territorial guard duty is very demanding, so much so that the males take rest periods outside of their territory. [9] When weather conditions do not allow them to leave their territory, they become increasingly aggressive. [9] Males that live in horizontal territories such as flowerbeds are more likely to notice intruders, and so are more likely to attack intruders than males who live in more vertically-aligned territories such as shrubs. [9]

Life history

Egg

Rat-tailed maggot Rattenschwanzlarve 1.jpg
Rat-tailed maggot

The egg is white. It is covered in a sticky substance, and it has an elongated shape. [6]

Larva

The larva is aquatic. It has a cylindrical shape with patches of horizontal folds that divide the body into segments. [6] At each of the segments, two rows of flexible hairs are visible. [6] All drone-fly larvae have a siphon on their posterior end that acts as a respiratory mechanism and looks like a tail, hence the common name, rat-tail maggot. [6] The siphon can be several times the length of the larva's body. [6]

Pupa

The pupal stage is very similar to the larva stage but shorter and thicker. [6] Unlike the larval stage, the pupa have two pairs of cornua (horn-like bumps) on their thorax. [6] The siphon is still present, but is locked in a curved position over the back. [6]

Adult

The adult fly is about 15 mm (6/10 of an inch) in length. Although it superficially resembles a honey bee, it can be easily differentiated from a honey bees because it does not have a constricted "waist" between the thorax and the abdomen. [6] Also, being a fly, it only has two wings whereas bees have four wings. [6] There are short brownish-yellow hairs on the thorax and the first segment of the abdomen. [6] The adult drone-fly's body is dark brown to black in color, with yellow-orange marks on the side of the second section of the abdomen. There is a yellow-orange band that crosses the 3rd abdominal segment. [6]

Sexual dimorphism

There is sexual dimorphism in drone flies: males tend to have lighter patterns than females. [7] Males can also be easily distinguished from females by their large eyes which almost touch each other, whereas females have smaller eyes that are spaced further apart. [6]

Biology

The larva of E. tenax is a rat-tailed maggot, which is saprophagous. It lives in drainage ditches, pools around manure piles, sewage, and similar places where water is polluted with organic matter. [10] The larvae likely feed on the abundant bacteria living in these places.

When fully grown, the larvae creep out into drier habitats, and seek a suitable place to pupate. In doing so, they sometimes enter buildings, especially barns and basements of farm houses. The pupae are typically 10–12 mm long, grey-brown, oval, and retain the long tail; they look like a tiny mouse.

The adult fly that emerges from the pupa is harmless. It looks somewhat like a drone honey bee, and likely gains some degree of protection from this resemblance to a stinging insect. The adults are called drone flies because of this resemblance. In its natural habitat, E. tenax is more of a curiosity than a problem. Like other hover flies, they are common visitors to flowers, [11] especially in late summer and autumn, and can be significant pollinators. They often feed on the flowers of carrot and fennel.

Under extremely rare conditions, there have been documented cases of human intestinal myiasis of the rat-tailed maggot (larva of Eristalis tenax). Zumpt proposed a hypothesis called "rectal myiasis". During open defecation in the wilderness, flies attracted to feces may deposit their eggs or larvae near or into the anus, and the larvae then penetrate further into the rectum. The larva can survive, feeding on feces at this site, as long as the breathing tube reaches out from the anus, which is quite rare. [10] [12]

Myiasis

The common drone fly is reported to have caused accidental myiasis. [6] This occurs when fly larvae inhabits a living host by accident, usually from ingestion of contaminated foods. [13] In humans, myiasis can be caused in four ways: intestinal or gastric, nasal, auricular, or anal. [6] The gastric or intestinal kinds are the most common. Most reported myaisis has been reported in countries where nutritional and sanitary conditions are substandard. [13] There are a very few reports of intestinal infestation from India, and Africa. [13] Clinically the symptoms are variable, including cases that are asymptomatic, but usually abdominal pain, nausea and vomiting are symptoms. [6] Myaisis becomes apparent to the host when they notice the larvae in their bowel movements. [6]

The fact that dronefly larvae are able to survive gastric acids may perhaps be due to the fact that they are adapted to living in polluted environments. [6]

Life cycle

The eggs are normally laid on surface water and go through three distinct larval stages. [14] The larvae are usually found in still or stagnant water, like water reservoirs or liquid dung. [14] Just before the pupation stage, the larvae leave their aquatic environment. [14]

Life cycle stages

There are still many gaps in the understanding of the drone fly life cycle, and more detailed research is needed. [6]

Eggs

The eggs are deposited near the surface of foul water or decaying organic material. [6] The eggs are laid side by side, perpendicular to the ground. It is still unknown how long it takes for the eggs to hatch. [6]

Larvae

The larvae are aquatic, but there must be enough solid food for the larva to complete development. [6] This is why they are found in water with high levels of organic matter. [6] The siphon on the back of the larvae remains at the surface of the water while the larva moves throughout the water. [6] This allows for the larva to search for food without having to go to the surface to breathe. [6] It has been reported that the larvae can reproduce by neoteny or paedogenesis, where the larva copies itself. There has only been one observation of this happening. [15]

Pupae

Pupation happens in a drier location than where the larvae develop. [6] It usually happens below the soil surface, where they remain for eight to 10 days. [6] The cornua that appear on the pupa are believed to help respiration because the siphon becomes unusable. [6]

Adults

Females feed on pollen after they emerge from the pupa and that way they are able to get the nutrients they need to complete reproduction. [6] Their next few meals will consist of nectar from daisies, chrysanthemums, and asters. [6]

Toughness

The toughness and resilience of E. tenax increases with age; the skin is insoluble even in strong alkaline solutions. [16] There have been reports of decapitated drone-flies living for three days and nights on the stage of a microscope. [16] With its abdomen removed, an adult drone-fly buzzed for more than an hour. [16] The thorax can be sliced open for examination, and the muscular bundles inside may still twitch when an irritant or needle-point is used. [16] Removing the wings seems to produce very little inconvenience to the fly, when put on a flower the fly without wings immediately plunged its proboscis into the center of the flower, and continued to feed for several minutes. [16]

Reproduction

Drone flies mating on a daisy inflorescence Drone flies mating.jpg
Drone flies mating on a daisy inflorescence

Mating can happen while a pair of E. tenax is flying, with the male uppermost, or on the ground while the female fly is resting on foliage. [6] After mating, the adult female lays clusters of about 10 eggs near dirty, contaminated water, sewage, or decomposing organic substances. [6]

Diet

The diet of Eristalis tenax consists mostly of nectar and the pollen of flowers. During the imago stage, the fly drinks mostly nectar, but will take a little water when it is presented. [16]

Pollen eating

It was found by researchers that when E. tenax accidentally traps pollen among the body hairs, the pollen grains are combed off by the front and hind tibia, and transferred to pollen-retaining bristles on the front and hind tarsi. [17] The pollen grains that are retained among the front tarsal bristle are eaten directly from the bristles. [17] Those caught by the hind tarsi are transferred in flight, by leg scraping, to the front tarsi, where they are then eaten. E. tenax also eats pollen directly from the anthers of flowers. [17]

Pollination

Diptera are an important but often neglected group of pollinators. They play a significant role in the pollination of agricultural biodiversity and the biodiversity of plants everywhere. [18] Hoverflies are considered to be less specialized pollinators than bees, and they are more effective in open than tubular flowers. [18] There is a significant difference in pollination efficiency between bees and flies. [19]

Mimicry

Collecting pollen Drone fly feeding on marigold.jpg
Collecting pollen
Pollination Abelha editada.jpg
Pollination

There is little doubt that the morphological and behavioral similarities between E. tenax and the honey bee are mainly a result of convergent evolution in response to similar food-gathering requirements. [17] Bees are common models for several Dipteran mimics [7] They are similar in their general form, flight, and coloration. [7] There are reports on the genetics of honeybees that show that the factors controlling the coloration are the same as the ones controlling the coloration in E. tenax. [17] In both species branched hairs and spirally grooved bristles act as collectors and retainers of pollen, and leg-scraping that occurs during hovering allows the transfer of pollen to take place, from hind legs to front legs in E. tenax, and in the reverse direction in honey bees. [17] E. tenax also has partial mimicry of wasps. [7] To improve the wasp mimicry there seems to be an epistatic influence on the Ap gene on the hair color genes. [7] The lightest phenotype of E. tenax is a light yellow, and seen most clearly as yellow bands along its sides, where a wasp has stripes of yellow pigment. [7] The lighter patterns would be less beneficial as wasp mimicry early in the year, before there a great number of wasps emerge. [7]

Activity

Common drone flies are active during much of the year, from March to December, and sometimes they are more numerous than honeybees, especially during autumn in urban areas. [7] Males and females occur in roughly equal numbers in summer and autumn, but males are very rare in the spring, when fertilized females come out of hibernation. [7]

Related Research Articles

<span class="mw-page-title-main">Fly</span> 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, mosquitoes and others, although only about 125,000 species have been described.

<span class="mw-page-title-main">Hoverfly</span> Family of insects

Hoverflies, also called flower flies or syrphids, 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, preying on aphids, thrips, and other plant-sucking insects.

<span class="mw-page-title-main">Myiasis</span> Infestation of parasitic maggots

Myiasis, also known as flystrike or fly strike, is the parasitic infestation of the body of a live animal by fly larvae (maggots) that grow inside the host while feeding on its tissue. Although flies are most commonly attracted to open wounds and urine- or feces-soaked fur, some species can create an infestation even on unbroken skin and have been known to use moist soil and non-myiatic flies as vector agents for their parasitic larvae.

<i>Eristalis</i> Genus of flies

Eristalis is a large genus of hoverflies, family Syrphidae, in the order Diptera. Several species are known as drone flies because they bear a resemblance to honeybee drones.

<span class="mw-page-title-main">Rat-tailed maggot</span> Larvae of hoverflies in the tribes Eristalini and Sericomyiini

Rat-tailed maggots are the larvae of certain species of hoverflies belonging to the tribes Eristalini and Sericomyiini. A characteristic feature of rat-tailed maggots is a tube-like, telescoping breathing siphon located at its posterior end. This acts like a snorkel, allowing the larva to breathe air while submerged. The siphon is usually about as long as the maggot's body, but can be extended as long as 150 mm (5.9 in). This organ gives the larva its common name.

<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.

<span class="mw-page-title-main">Eristalinae</span> 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>Eristalinus taeniops</i> Species of fly

Eristalinus taeniops is a species of hoverfly, also known as the band-eyed drone fly.

<i>Eristalis arbustorum</i> Species of insect

Eristalis arbustorum, the European drone fly, is an abundant Northern Hemisphere species of syrphid fly, originally officially described by Linnaeus in 1758 as Musca arbustorum. The name "drone fly" is related to its similar appearance to the drone of the honeybee. Hoverflies get their names from the ability to remain nearly motionless while in flight. The adults are also known as flower flies as they are commonly found on and around flowers from which they get both energy-giving nectar and protein rich pollen. The larvae are aquatic filter-feeders of the long-tailed type.

<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. Syritta pipiens looks like many predatory hoverfly species, yet is not predatory.

<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>Sericomyia chrysotoxoides</i> Species of insect

Sericomyia chrysotoxoides ,, the Oblique-banded Pond Fly , is a common species of syrphid fly observed across the eastern half of North America and in the Rocky Mountains. Syrphid flies are also known as Hover Flies or Flower Flies because the adults are frequently found hovering around flowers from which they feed on nectar and pollen. Adults are 9.6–1,315.3 mm (0.38–51.78 in) long, black with yellow bands, less prominent in the male. The larvae of this genus are known as rat tailed maggots for the long posterior breathing tube.

<span class="mw-page-title-main">Eristalini</span> Tribe of overflies

Eristalini is a tribe of hoverflies. Several species are well-known honeybee mimics, such as the drone fly Eristalis tenax, while other genera such as Helophilus and Parhelophilus exhibit wasp-like patterns of yellow and black stripes, both strategies to avoid predation by visual predators such as birds.

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.

<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.

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

Eristalis hirta, the black-footed drone fly, is a common Western North American species of syrphid fly, first officially described by Loew in 1866. Hoverflies get their names from the ability to remain nearly motionless while in flight. The adults are also known as flower flies as they are commonly found on and around flowers, from which they get both energy-giving nectar and protein-rich pollen. The larvae are aquatic filter-feeders of the rat-tailed type.

<i>Eristalinus tabanoides</i> Species of fly

Eristalinus tabanoides is a species of hoverfly that inhabits the Old world.

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

Eristalis brousii, also known as the hourglass drone fly, is a fly species in the Syrphidae family first described by Samuel Wendell Williston in 1882. Aside from Northern Canada, the species has been largely eradicated throughout North America. Eristalis brousii are part of the hoverfly family, known for hovering above flowers to collect nectar and pollen.

<span class="mw-page-title-main">Eristalina</span> Subtribe of hoverflies

Eristalina is a subtribe of hoverflies with 17 genera. Several species are well-known bee mimics, such as the drone fly. The larvae live in aquatic and moist organic material, often with low oxygen levels using a posterior breathing tube, thus the common name—the "rat-tailed maggot".

References

  1. Stubbs, Alan E.; Falk, Steven J. (1983). British Hoverflies: An Illustrated Identification Guide. British Entomological & Natural History Society. p. 253, xvpp. ISBN   978-0-9502891-4-4.
  2. Skevington, Jeffrey H.; Locke, Michelle M.; Young, Andrew D.; Moran, Kevin; Crins, William J.; Marshall, Stephen A. (2019). Field Guide to the Flower Flies of Northeastern North America. Princeton. ISBN   9780691189406.{{cite book}}: CS1 maint: location missing publisher (link)
  3. Francuski, Ljubinka; Djurakic, Marko; Ludoški, Jasmina; Milankov, Vesna (2013-08-01). "Landscape genetics and spatial pattern of phenotypic variation of Eristalis tenax across Europe". Journal of Zoological Systematics and Evolutionary Research. 51 (3): 227–238. doi: 10.1111/jzs.12017 . ISSN   1439-0469.
  4. Hull, Frank M. (1937). A Check List of the Syrphidae of Oceania. Honolulu, Hawaii: Bernice P. Bishop Museum.
  5. Shah1;Jan2;Ahmad Wachkoo3, Ghulam Mustafa1;Ulfat2;Aijaz3 (2014). "A CHECKLIST OF HOVERFLIES (DIPTERA/ SYRPHIDAE) IN THE WESTERN HIMALAYA, INDIA" (PDF). Acta Zoologica Academiae Scientiarum Hungaricae. 60 (4): 283–305.{{cite journal}}: CS1 maint: multiple names: authors list (link) CS1 maint: numeric names: authors list (link)
  6. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 "drone fly, rat-tailed maggot - Eristalis tenax (Linnaeus)". entnemdept.ufl.edu. Retrieved 2019-10-31.
  7. 1 2 3 4 5 6 7 8 9 10 11 12 Heal, J. R. (August 1982). "Colour patterns of syrphidae: IV. Mimicry and variation in natural populations of Eristalis tenax". Heredity. 49 (1): 95–109. doi: 10.1038/hdy.1982.68 . ISSN   1365-2540.
  8. Fitzpatrick, Sheila M. (1981). Territorial aggression among males of three Syrphid species. The University of British Columbia.
  9. 1 2 3 4 5 6 Wellington, W. G.; Fitzpatrick, Sheila M. (August 1981). "Territoriality in the Drone Fly, Eristalis tenax (Diptera: Syrphidae)". The Canadian Entomologist. 113 (8): 695–704. doi:10.4039/Ent113695-8. ISSN   1918-3240. S2CID   86181761.
  10. 1 2 Aguilera, A; Cid, A; Regueiro, BJ; Prieto, JM; Noya, M (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.
  11. 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.
  12. Phillip B. Whish-Wilson (2000). "A possible case of intestinal myiasis due to Eristalis tenax". Medical Journal of Australia . 173 (11): 652. doi:10.5694/j.1326-5377.2000.tb139374.x. PMID   11379520. S2CID   12898612 . Retrieved January 13, 2008.
  13. 1 2 3 Aguilera, A.; Cid, A.; Regueiro, B. J.; Prieto, J. M.; Noya, M. (1999-09-01). "Intestinal Myiasis Caused by Eristalis tenax". Journal of Clinical Microbiology. 37 (9): 3082. doi: 10.1128/JCM.37.9.3082-3082.1999 . ISSN   0095-1137. PMC   85471 . PMID   10475752.
  14. 1 2 3 Fischer, O. A.; Mátlová, L.; Dvorská, L.; Švástová, P.; Bartoš, M.; Weston, R. T.; Pavlík, I. (2006-03-01). "Various stages in the life cycle of syrphid flies (Eristalis tenax; diptera: Syrphidae) as potential mechanical vectors of pathogens causing mycobacterial infections in pig herds". Folia Microbiologica. 51 (2): 147–153. doi:10.1007/BF02932171. ISSN   1874-9356. PMID   16821726. S2CID   20227735.
  15. The Occurrence of Paedogenesis in Eristalis Larvae (Diptera: Syrphidae), I A Ibrahim and A M Gad, Journal of Medical Entomology, Volume 12, Issue 2, 30 June 1975, Page 268
  16. 1 2 3 4 5 6 Bowdler Buckton, George (1895). "The Natural History of Eristalis tenax Or the Drone-fly". Nature. 53 (1365): 172. Bibcode:1895Natur..53..172L. doi: 10.1038/053172b0 . S2CID   4024022.
  17. 1 2 3 4 5 6 Holloway, Beverley A. (1976-12-01). "Pollen‐feeding in hover‐flies (Diptera: Syrphidae)". New Zealand Journal of Zoology. 3 (4): 339–350. doi:10.1080/03014223.1976.9517924. ISSN   0301-4223.
  18. 1 2 Ssymank, Axel; Kearns, C. A.; Pape, Thomas; Thompson, F. Christian (April 2008). "Pollinating Flies (Diptera): A major contribution to plant diversity and agricultural production". Biodiversity. 9 (1–2): 86–89. doi:10.1080/14888386.2008.9712892. ISSN   1488-8386. S2CID   39619017.
  19. Jauker, Frank; Bondarenko, Birgit; Becker, Heiko C.; Steffan‐Dewenter, Ingolf (2012). "Pollination efficiency of wild bees and hoverflies provided to oilseed rape". Agricultural and Forest Entomology. 14 (1): 81–87. doi:10.1111/j.1461-9563.2011.00541.x. ISSN   1461-9563. S2CID   85284468.