Rat-tailed maggot
Encyclopedia
Larva
A larva is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle...
of some species of hoverfly
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 eat a wide range of foods...
, commonly Eristalis tenax
Eristalis tenax
Eristalis tenax is a European hoverfly, also known as the drone fly . It has been introduced into North America and is widely established....
. A characteristic feature of rat-tailed maggots is a tube-like, three segmented, telescoping breathing siphon located at their posterior end. This acts like a snorkel, allowing the larva to breathe air while submerged. The siphon is usually about as long again as the maggot's body (20 mm when mature), but can be extended as long as 150 mm. It is this organ that gives the larva its common name. It lives in stagnant, oxygen
Oxygen
Oxygen is the element with atomic number 8 and represented by the symbol O. Its name derives from the Greek roots ὀξύς and -γενής , because at the time of naming, it was mistakenly thought that all acids required oxygen in their composition...
-deprived water, with a high organic content. It is fairly tolerant of pollution and can live in sewage lagoons and cesspools.
Commercial use
These larvae, commonly called "mousies" are cultured and sold as fish bait. They are especially popular in ice fishing.Infection
There have occasionally been documented cases of human intestinal MyiasisMyiasis
Myiasis is a general term for infection by parasitic fly larvae feeding on the host's necrotic or living tissue. Colloquialisms for myiasis include flystrike, blowfly strike, and fly-blown. In Greek, "myia" means fly....
of the Rat-tailed maggot (larvae of Eristalis tenax
Eristalis tenax
Eristalis tenax is a European hoverfly, also known as the drone fly . It has been introduced into North America and is widely established....
). Symptoms can be none (asymptomatic
Asymptomatic
In medicine, a disease is considered asymptomatic if a patient is a carrier for a disease or infection but experiences no symptoms. A condition might be asymptomatic if it fails to show the noticeable symptoms with which it is usually associated. Asymptomatic infections are also called subclinical...
) to abdominal pain, nausea
Nausea
Nausea , is a sensation of unease and discomfort in the upper stomach with an involuntary urge to vomit. It often, but not always, precedes vomiting...
and vomiting
Vomiting
Vomiting is the forceful expulsion of the contents of one's stomach through the mouth and sometimes the nose...
, or pruritus ani
Pruritus ani
Pruritus ani is the irritation of the skin at the exit of the rectum, known as the anus, causing the desire to scratch. The intensity of anal itching increases from moisture, pressure, and rubbing caused by clothing and sitting...
. Infection can be caused by ingestion of contaminated food or water but doubts have been expressed that accidentally ingested fly larvae could survive in the gastrointestinal tract
Gastrointestinal tract
The human gastrointestinal tract refers to the stomach and intestine, and sometimes to all the structures from the mouth to the anus. ....
. Zumpt
Fritz Konrad Ernst Zumpt
Fritz Konrad Ernst Zumpt was a German entomologist who worked mainly in Africa . He is best known for his work on Diptera and the associations between insects and African mammals. Also for his work on myiasis.Amongst Zumpt’s works are...
proposed an alternative called "rectal myiasis". Flies, attracted to feces
Feces
Feces, faeces, or fæces is a waste product from an animal's digestive tract expelled through the anus or cloaca during defecation.-Etymology:...
, may deposit their eggs or larvae near or into the anus
Anus
The anus is an opening at the opposite end of an animal's digestive tract from the mouth. Its function is to control the expulsion of feces, unwanted semi-solid matter produced during digestion, which, depending on the type of animal, may be one or more of: matter which the animal cannot digest,...
, and the larvae then penetrate further into the rectum. They can survive feeding on feces at this site, as long as the breathing tube reaches towards the anus.
Images
http://maggotresource.com/rtmbiblio.aspxExternal links
http://maggotresource.com/default.aspx- rat-tailed maggot on the UFUniversity of FloridaThe University of Florida is an American public land-grant, sea-grant, and space-grant research university located on a campus in Gainesville, Florida. The university traces its historical origins to 1853, and has operated continuously on its present Gainesville campus since September 1906...
/ IFASInstitute of Food and Agricultural SciencesThe University of Florida’s Institute of Food and Agricultural Sciences is a federal-state-county partnership dedicated to developing knowledge in agriculture, human and natural resources, and the life sciences, and enhancing and sustaining the quality of human life by making that information...
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