''Tabanus nigrovittatus'', also known as the greenhead horse fly, salt marsh greenhead, or simply the greenhead fly, greenhead or greenfly,
[ ] is a species of
horse-fly
Horse flies and deer flies are true flies in the family Tabanidae in the insect Order (biology), order Diptera. The adults are often large and agile in flight. Only females bite land vertebrates, including humans, to hematophagy, obtain blood ...
commonly found around the coastal
marsh
In ecology, a marsh is a wetland that is dominated by herbaceous plants rather than by woody plants.Keddy, P.A. 2010. Wetland Ecology: Principles and Conservation (2nd edition). Cambridge University Press, Cambridge, UK. 497 p More in genera ...
es and
wetlands
A wetland is a distinct semi-aquatic ecosystem whose groundcovers are flooded or saturated in water, either permanently, for years or decades, or only seasonally. Flooding results in oxygen-poor ( anoxic) processes taking place, especially ...
of the Eastern
United States
The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...
. They are smaller than most horsefly species, instead being close in size to a common
housefly
The housefly (''Musca domestica'') is a fly of the suborder Cyclorrhapha. It possibly originated in the Middle East, and Cosmopolitan distribution, spread around the world as a commensal of humans. Adults are gray to black, with four dark, lo ...
. The biting females are a considerable
pest to both
human
Humans (''Homo sapiens'') or modern humans are the most common and widespread species of primate, and the last surviving species of the genus ''Homo''. They are Hominidae, great apes characterized by their Prehistory of nakedness and clothing ...
s and animals while they seek a source of
blood
Blood is a body fluid in the circulatory system of humans and other vertebrates that delivers necessary substances such as nutrients and oxygen to the cells, and transports metabolic waste products away from those same cells.
Blood is com ...
protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residue (biochemistry), residues. Proteins perform a vast array of functions within organisms, including Enzyme catalysis, catalysing metab ...
to produce additional eggs:
greenhead larvae develop in the mud of
salt marsh
A salt marsh, saltmarsh or salting, also known as a coastal salt marsh or a tidal marsh, is a coastal ecosystem in the upper coastal intertidal zone between land and open saltwater or brackish water that is regularly flooded by the tides. I ...
es, and adult flies mate and lay their first group of eggs in the marsh, but to lay more eggs a female fly needs to drink an animal's blood, and so female greenheads which have laid eggs fly inland to look for prey in the area bordering the marsh; they can stay on land looking for animals to bite for up to four weeks.
[ Their bites itch, like those of ]mosquito
Mosquitoes, the Culicidae, are a Family (biology), family of small Diptera, flies consisting of 3,600 species. The word ''mosquito'' (formed by ''Musca (fly), mosca'' and diminutive ''-ito'') is Spanish and Portuguese for ''little fly''. Mos ...
es, but are more painful, since greenheads feed by cutting a wound in the skin with scissor-like mouth parts and sucking the blood released through it.[ Females live for three to four weeks and may lay about 100 to 200 eggs per blood meal. The eggs are laid on the grass in a salt marsh; the larvae live in the intertidal mud of the salt marsh for one or two years, preying on other invertebrates, before ]pupa
A pupa (; : pupae) is the life stage of some insects undergoing transformation between immature and mature stages. Insects that go through a pupal stage are holometabolous: they go through four distinct stages in their life cycle, the stages th ...
ting in early spring.[ The adult flies emerge in late spring and are most common from late June to August.][ Affected coastal communities install ]black box
In science, computing, and engineering, a black box is a system which can be viewed in terms of its inputs and outputs (or transfer characteristics), without any knowledge of its internal workings. Its implementation is "opaque" (black). The te ...
traps in marsh areas to reduce and control ''T. nigrovittatus'' populations.
References
Tabanidae
Insects described in 1847
Diptera of North America
Fauna of the Eastern United States
Taxa named by Pierre-Justin-Marie Macquart
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