Temefos or temephos (trade name Abate) is an
organophosphate
In organic chemistry, organophosphates (also known as phosphate esters, or OPEs) are a class of organophosphorus compounds with the general structure , a central phosphate molecule with alkyl or aromatic substituents. They can be considered a ...
larvicide
A larvicide (alternatively larvacide) is an insecticide that is specifically targeted against the larval life stage of an insect. Their most common use is against mosquitoes. Larvicides may be contact poisons, stomach poisons, growth regulators, o ...
used to treat water infested with disease-carrying
insects
Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body (head, thorax and abdomen), three pairs of j ...
including
mosquito
Mosquitoes (or mosquitos) are members of a group of almost 3,600 species of small flies within the family Culicidae (from the Latin ''culex'' meaning " gnat"). The word "mosquito" (formed by ''mosca'' and diminutive ''-ito'') is Spanish for "li ...
es,
midge
A midge is any small fly, including species in several families of non-mosquito Nematoceran Diptera. Midges are found (seasonally or otherwise) on practically every land area outside permanently arid deserts and the frigid zones. Some mid ...
s, and
black fly
A black fly or blackfly (sometimes called a buffalo gnat, turkey gnat, or white socks) is any member of the family Simuliidae of the Culicomorpha infraorder. It is related to the Ceratopogonidae, Chironomidae, and Thaumaleidae. Over 2,200 spec ...
larva
A larva (; plural larvae ) 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.
The ...
e.
As with other organophosphates, temephos affects the
central nervous system
The central nervous system (CNS) is the part of the nervous system consisting primarily of the brain and spinal cord. The CNS is so named because the brain integrates the received information and coordinates and influences the activity of all par ...
through inhibition of
cholinesterase
The enzyme cholinesterase (EC 3.1.1.8, choline esterase; systematic name acylcholine acylhydrolase) catalyses the hydrolysis of choline-based esters:
: an acylcholine + H2O = choline + a carboxylate
Several of these serve as neurotransmitters ...
. In larvae, this results in death before reaching the adult stage.
In the
developing world
A developing country is a sovereign state with a lesser developed industrial base and a lower Human Development Index (HDI) relative to other countries. However, this definition is not universally agreed upon. There is also no clear agreem ...
where the
vector
Vector most often refers to:
*Euclidean vector, a quantity with a magnitude and a direction
*Vector (epidemiology), an agent that carries and transmits an infectious pathogen into another living organism
Vector may also refer to:
Mathematic ...
-borne disease
dengue fever
Dengue fever is a mosquito-borne tropical disease caused by the dengue virus. Symptoms typically begin three to fourteen days after infection. These may include a high fever, headache, vomiting, muscle and joint pains, and a characterist ...
is
endemic
Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...
, temephos is widely used and applied by both private and public pest control in areas of
standing water
Water stagnation occurs when water stops flowing. Stagnant water can be a major environmental hazard.
Dangers
Malaria and dengue are among the main dangers of stagnant water, which can become a breeding ground for the mosquitoes that transmi ...
where the ''
Aedes aegypti
''Aedes aegypti'', the yellow fever mosquito, is a mosquito that can spread dengue fever, chikungunya, Zika fever, Mayaro and yellow fever viruses, and other disease agents. The mosquito can be recognized by black and white markings on its legs ...
'' mosquito breeds in order to reduce the population of this disease-carrying insect. Temephos is also used in the
Guinea worm eradication
Dracunculiasis, or Guinea worm disease, is an infection by the Guinea worm. In 1986, there were an estimated 3.5 million cases of Guinea worm in 20 endemic nations in Asia and Africa. Ghana alone reported 180,000 cases in 1989. The number of ...
program to kill
water fleas
The Diplostraca or Cladocera, commonly known as water fleas, are a superorder of small crustaceans that feed on microscopic chunks of organic matter (excluding some predatory forms).
Over 1000 species have been recognised so far, with many more ...
that carry guinea worm larvae.
Resistance to temephos by ''A. aegypti'' has been seen in
Brazil
Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area ...
. The Brazilian Aedes aegypti resistance monitoring program detected temephos resistance in ''A. aegypti'' populations from several localities in the country in 1999 (Funasa 2000, Lima et al. 2003). In 1999, mosquitoes from the city of
Rio de Janeiro
Rio de Janeiro ( , , ; literally 'River of January'), or simply Rio, is the capital of the state of the same name, Brazil's third-most populous state, and the second-most populous city in Brazil, after São Paulo. Listed by the GaWC as a b ...
were already resistant to temephos.
References
External links
NIOSH Pocket Guide to Chemical Hazards*
Bibliography
* Dejous C & Elouard J.M (1977
Action de l'abate sur les invertébérs aquatiques ; cinétique de décrochement à court et moyen terme(in French).
{{Authority control
Acetylcholinesterase inhibitors
Organophosphate insecticides
Thioethers
Organothiophosphate esters