The
Asian tiger mosquito or
forest day mosquito,
Aedes albopictus (
Stegomyia albopicta), from the
mosquitoMosquitoes are members of a family of nematocerid flies: the Culicidae . The word Mosquito is from the Spanish and Portuguese for little fly...
(Culicidae)
familyIn biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
, is characterized by its black and white striped legs, and small black and white striped body. It is native to the
tropicalThe tropics is a region of the Earth surrounding the Equator. It is limited in latitude by the Tropic of Cancer in the northern hemisphere at approximately N and the Tropic of Capricorn in the southern hemisphere at S; these latitudes correspond to the axial tilt of the Earth...
and
subtropicalThe subtropics are the geographical and climatical zone of the Earth immediately north and south of the tropical zone, which is bounded by the Tropic of Cancer and the Tropic of Capricorn, at latitudes 23.5°N and 23.5°S...
areas of
Southeast AsiaSoutheast Asia, South-East Asia, South East Asia or Southeastern Asia is a subregion of Asia, consisting of the countries that are geographically south of China, east of India, west of New Guinea and north of Australia. The region lies on the intersection of geological plates, with heavy seismic...
; however, in the past couple of decades this species has invaded many countries throughout the world through the transport of goods and increasing international travel. This mosquito has become a significant pest in many communities because it closely associates with humans (rather than living in wetlands), and typically flies and feeds in the daytime in addition to at dusk and dawn. The insect is called a tiger mosquito because its striped appearance is similar to a
tigerThe tiger is the largest cat species, reaching a total body length of up to and weighing up to . Their most recognizable feature is a pattern of dark vertical stripes on reddish-orange fur with lighter underparts...
.
Aedes albopictus is an
epidemiologicallyEpidemiology is the study of health-event, health-characteristic, or health-determinant patterns in a population. It is the cornerstone method of public health research, and helps inform policy decisions and evidence-based medicine by identifying risk factors for disease and targets for preventive...
important vector for the
transmissionIn medicine and biology, transmission is the passing of a communicable disease from an infected host individual or group to a conspecific individual or group, regardless of whether the other individual was previously infected...
of many viral
pathogenA pathogen gignomai "I give birth to") or infectious agent — colloquially, a germ — is a microbe or microorganism such as a virus, bacterium, prion, or fungus that causes disease in its animal or plant host...
s, including the
West Nile virusWest Nile virus is a virus of the family Flaviviridae. Part of the Japanese encephalitis antigenic complex of viruses, it is found in both tropical and temperate regions. It mainly infects birds, but is known to infect humans, horses, dogs, cats, bats, chipmunks, skunks, squirrels, domestic...
,
Yellow fever virusYellow fever is an acute viral hemorrhagic disease. The virus is a 40 to 50 nm enveloped RNA virus with positive sense of the Flaviviridae family....
,
St. Louis encephalitisSt. Louis Encephalitis is a disease caused by the Culex mosquito borne St. Louis Encephalitis virus. St. Louis encephalitis virus is related to Japanese encephalitis virus and is a member of the Flaviviridae subgroup. This disease mainly affects the United States...
,
dengue feverDengue fever , also known as breakbone fever, is an infectious tropical disease caused by the dengue virus. Symptoms include fever, headache, muscle and joint pains, and a characteristic skin rash that is similar to measles...
, and
Chikungunya feverChikungunya virus is an insect-borne virus, of the genus Alphavirus, that is transmitted to humans by virus-carrying Aedes mosquitoes. There have been recent breakouts of CHIKV associated with severe illness...
, as well as several
filarial nematodesFilariasis is a parasitic disease and is considered an infectious tropical disease, that is caused by thread-like nematodes belonging to the superfamily Filarioidea, also known as "filariae"....
such as
Dirofilaria immitis.
Name and systematics
In 1894, a British-Australian entomologist,
Frederick A. Askew SkuseFrederick A. Askew Skuse was a British-Australian Entomologist.- Biography :thumb|Skuse's description of the Asian tiger mosquito under the name of Culex albopictus....
, was the first to describe scientifically the Asian tiger mosquito, which he named
CulexCulex is a genus of mosquito, and is important in that several species serve as vectors of important diseases, such as West Nile virus, filariasis, Japanese encephalitis, St. Louis encephalitis and avian malaria....
albopictus (
lat.Lat. or lat. is an abbreviation for:*Latin*latitude*Mohammad Nor Khalid or Lat, a Malaysian cartoonist...
“gnat, midge” and
“white embroided”). Later, the species was assigned to the genus
AedesAedes is a genus of mosquito originally found in tropical and subtropical zones, but now found on all continents excluding Antarctica. Some species have been spread by human activity. Aedes albopictus, a most invasive species was recently spread to the New World, including the U.S., by the used...
(
gr.Ancient Greek is the stage of the Greek language in the periods spanning the times c. 9th–6th centuries BC, , c. 5th–4th centuries BC , and the c. 3rd century BC – 6th century AD of ancient Greece and the ancient world; being predated in the 2nd millennium BC by Mycenaean Greek...
, "unpleasant") and referred to as
Aedes albopictus. Like the yellow fever mosquito, it belongs to the subgenus
Stegomyia (gr. , "covered, roofed", referring to the scales that completely cover the dorsal surface in this Subgenus, and , "fly"). In 2004, scientists explored higher-level relationships and proposed a new classification within the
Aedes genus and
Stegomyia was elevated to the Genus level, making
Aedes albopictus now
Stegomyia albopicta. This is, however, a controversial matter, and the use of
Stegomyia albopicta versus
Aedes albopictus is continually debated.
Characteristics
The Asian tiger mosquito is about 2 to 10 mm length with a striking white and black pattern. The variation of the body size in adult mosquitoes depends on the density of the larval population and food supply within the breeding water. Since these circumstances are seldom optimal, the average body size of adult mosquitoes is considerably smaller than 10 mm. For example, the average length of the
abdomenIn vertebrates such as mammals the abdomen constitutes the part of the body between the thorax and pelvis. The region enclosed by the abdomen is termed the abdominal cavity...
was calculated to be 2.63 mm, the wings 2.7 mm, and the proboscis 1.88 mm through a study of 10 images from 1962 of both male and female mosquitoes.
The males are roughly 20% smaller than the females, but they are
morphologicallyIn biology, morphology is a branch of bioscience dealing with the study of the form and structure of organisms and their specific structural features....
very similar. However, as in all mosquito species, the
antennaeAntennae in biology have historically been paired appendages used for sensing in arthropods. More recently, the term has also been applied to cilium structures present in most cell types of eukaryotes....
of the males in comparison to the females are noticeably bushier and contain auditory receptors to detect the characteristic whine of the female. The maxillary palps of the males are also longer than their proboscises whereas the females’ maxillary palps are much shorter. (This is typical for the males of the
CulicinaeCulicinae is the most extensive subfamily of mosquitos divided into two tribes: Culicini and Sabethini.-External links:*...
.) In addition, the tarsus of the hind legs of the males is more silvery. Tarsomere IV is roughly three-quarters silver in the males whereas the females’ is only about 60% silver.
The other characteristics do not differentiate between sexes. A single silvery-white line of tight scales begins between the eyes and continues down the dorsal side of the thorax. This characteristic marking is the easiest and surest way to identify the Asian tiger mosquito.
The
proboscisA proboscis is an elongated appendage from the head of an animal, either a vertebrate or an invertebrate. In simpler terms, a proboscis is the straw-like mouth found in several varieties of species.-Etymology:...
is dark colored, the upper surface of the end segment of the palps is covered in silvery scales, and the labium does not feature a light line on its underside. The compound eyes are distinctly separated from one another. The
scutumScutum is a small constellation introduced in the seventeenth century. Its name is Latin for shield.-History:Scutum is the only constellation that owes its name to a non-classical historical figure...
, the dorsal portion of an insect’s thoracic segment, is black alongside the characteristic white midline. On the side of the thorax, the scutellum, and the abdomen there are numerous spots covered in white-silvery scales.
Such white-silvery scales can also be found on the tarsus, particularly on the hind legs that are commonly suspended in the air. The base of tarsomere I through IV has a ring of white scales, creating the appearance of white and black rings. On the fore legs and middle legs, only the first three tarsomeres have the ring of white scales whereas tarsomere V on the hind legs is completely white. The femur of each leg is also black with white scales on the end of the “knee”. The femurs of the middle legs do not feature a silver line on the base of the upper side, whereas, the femurs on the hind legs have short white lines on base of the upper side. The
tibiaThe tibia , shinbone, or shankbone is the larger and stronger of the two bones in the leg below the knee in vertebrates , and connects the knee with the ankle bones....
s are black on the base and have no white scales.
The terga on segments II through VI of the abdomen are dark and have an almost triangular silvery-white marking on the base that is not aligned with the silvery bands of scales on the ventral side of the abdomen. The triangular marking and the silvery band are only aligned on abdominal segment VII. The transparent wings have white spots on the base of the Costas. With older mosquito specimens, the scales could be partially worn off making the previously mentioned characteristics not stand out as much.
The typical
Aedes albopictus individual has a length of about 2 to 10mm. As with other members of the mosquito family, the female is equipped with an elongated
proboscisA proboscis is an elongated appendage from the head of an animal, either a vertebrate or an invertebrate. In simpler terms, a proboscis is the straw-like mouth found in several varieties of species.-Etymology:...
that she uses to collect
bloodBlood is a specialized bodily fluid in animals that delivers necessary substances such as nutrients and oxygen to the cells and transports metabolic waste products away from those same cells....
to feed her eggs. The Asian tiger mosquito has a rapid bite that allows it to escape most attempts by people to swat it. By contrast the male member of the species primarily feeds on nectar.
The female lays her eggs near water; not directly into it as other mosquitoes do, but typically near a stagnant pool. However, any open container containing water will suffice for larvae development, even with less than an ounce of water in. It can also breed in running water, so stagnant pools of water are not its only breeding sites. It has a short flight range (less than 200 m), so breeding sites are likely to be close to where this mosquito is found.
Similar species
Some mosquitoes in
North AmericaNorth America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
, such as
Ochlerotatus canadensis, have a similar leg pattern.
In Europe, the mosquito
Culiseta annulata, which is very common, but does not occur in high densities, can be mistaken for an Asian tiger mosquito because of its black and white ringed legs. However, this species is missing the distinctive white line that runs from the middle of its head and down the thorax. It is also considerably larger than
Aedes albopictus, is not black and white, but rather beige and grey striped, and has wings with noticeable veins and four dark, indistinct spots.
In the eastern Mediterranean area,
Aedes albopictus species can be mistaken with
Aedes cretinus, which also belongs to the subgenus
Stegomyia and uses similar breeding waters.
Aedes cretinus also has a white stripe on the
scutumScutum is a small constellation introduced in the seventeenth century. Its name is Latin for shield.-History:Scutum is the only constellation that owes its name to a non-classical historical figure...
, but it ends shortly before the abdomen, and also has two additional stripes to the left and right of the middle stripe. So far
Aedes cretinus is only located in Cyprus, Greece, FYROM, Georgia and Turkey.
In Asia, the Asian tiger mosquito can be mistaken for other members of the subgenus
Stegomyia, particularly the yellow fever mosquito
Aedes aegyptiThe yellow fever mosquito, Aedes aegypti is a mosquito that can spread the dengue fever, Chikungunya and yellow fever viruses, and other diseases. The mosquito can be recognized by white markings on legs and a marking in the form of a lyre on the thorax...
(the most prevalent species in the tropics and subtropics), because both species display a similar black and white pattern. It can be hard to distinguish
Aedes albopictus from the closely related
Aedes scutellarisAedes scutellaris is a mosquito found in Ambon, Aru Islands, Seram, New Guinea. It is a vector for the dengue virus....
(India, Indonesia,
Papua New GuineaPapua New Guinea , officially the Independent State of Papua New Guinea, is a country in Oceania, occupying the eastern half of the island of New Guinea and numerous offshore islands...
, and the
PhilippinesThe Philippines , officially known as the Republic of the Philippines , is a country in Southeast Asia in the western Pacific Ocean. To its north across the Luzon Strait lies Taiwan. West across the South China Sea sits Vietnam...
),
Aedes pseudoalbopictus (
IndiaIndia , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...
,
IndonesiaIndonesia , officially the Republic of Indonesia , is a country in Southeast Asia and Oceania. Indonesia is an archipelago comprising approximately 13,000 islands. It has 33 provinces with over 238 million people, and is the world's fourth most populous country. Indonesia is a republic, with an...
,
Malaysia,
MyanmarBurma , officially the Republic of the Union of Myanmar , is a country in Southeast Asia. Burma is bordered by China on the northeast, Laos on the east, Thailand on the southeast, Bangladesh on the west, India on the northwest, the Bay of Bengal to the southwest, and the Andaman Sea on the south....
,
NepalNepal , officially the Federal Democratic Republic of Nepal, is a landlocked sovereign state located in South Asia. It is located in the Himalayas and bordered to the north by the People's Republic of China, and to the south, east, and west by the Republic of India...
,
TaiwanTaiwan , also known, especially in the past, as Formosa , is the largest island of the same-named island group of East Asia in the western Pacific Ocean and located off the southeastern coast of mainland China. The island forms over 99% of the current territory of the Republic of China following...
,
ThailandThailand , officially the Kingdom of Thailand , formerly known as Siam , is a country located at the centre of the Indochina peninsula and Southeast Asia. It is bordered to the north by Burma and Laos, to the east by Laos and Cambodia, to the south by the Gulf of Thailand and Malaysia, and to the...
, and
VietnamVietnam – sometimes spelled Viet Nam , officially the Socialist Republic of Vietnam – is the easternmost country on the Indochina Peninsula in Southeast Asia. It is bordered by China to the north, Laos to the northwest, Cambodia to the southwest, and the South China Sea –...
) and
Aedes seatoi (Thailand).
Diet and host location
Like other mosquito species, only the females require a blood meal to develop their eggs. Apart from that, they feed on nectar and other sweet plant juices just as the males do. In regards to
hostIn biology, a host is an organism that harbors a parasite, or a mutual or commensal symbiont, typically providing nourishment and shelter. In botany, a host plant is one that supplies food resources and substrate for certain insects or other fauna...
location,
carbon dioxideCarbon dioxide is a naturally occurring chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom...
and organic substances produced from the host, humidity, and optical recognition play important roles.
The search for a host takes place in two phases. First, the mosquito exhibits a nonspecific searching behavior until it perceives host stimulants, wherupon it secondly takes a targeted approach. For catching tiger mosquitoes with special traps, carbon dioxide and a combination of chemicals that naturally occur in human skin (fatty acids,
ammoniaAmmonia is a compound of nitrogen and hydrogen with the formula . It is a colourless gas with a characteristic pungent odour. Ammonia contributes significantly to the nutritional needs of terrestrial organisms by serving as a precursor to food and fertilizers. Ammonia, either directly or...
, and
lactic acidLactic acid, also known as milk acid, is a chemical compound that plays a role in various biochemical processes and was first isolated in 1780 by the Swedish chemist Carl Wilhelm Scheele. Lactic acid is a carboxylic acid with the chemical formula C3H6O3...
) are the most attractive.
The Asian tiger mosquito particularly bites in forests during the day and has been known as the
forest day mosquito for this very reason. Depending upon region and biotype, there are differing active peaks, but for the most part they rest during the morning and night hours. They search for their hosts inside and outside of human dwellings, but are particularly active outside. The size of the blood meal depends upon the size of the mosquito, but it is usually around 2
microlitrespic|200px|right|thumb|One litre is equivalent to this cubeEach side is 10 cm1 litre water = 1 kilogram water The litre is a metric system unit of volume equal to 1 cubic decimetre , to 1,000 cubic centimetres , and to 1/1,000 cubic metre...
.
Aedes albopictus also bites other mammals besides humans and they also bite birds. They are always on the search for a host and are both persistent and cautious when it comes to their blood meal and host location. Their blood meal is often broken off short without enough blood ingested for the development of their eggs. This is why Asian tiger mosquitoes bite multiple hosts during their development cycle of the egg, making them particularly efficient at transmitting diseases. The mannerism of biting diverse host species enables the Asian tiger mosquito to be a potential bridge vector for certain pathogens, for example, the
West Nile virusWest Nile virus is a virus of the family Flaviviridae. Part of the Japanese encephalitis antigenic complex of viruses, it is found in both tropical and temperate regions. It mainly infects birds, but is known to infect humans, horses, dogs, cats, bats, chipmunks, skunks, squirrels, domestic...
that can jump species boundaries.
Natural enemies
Primarily, other mosquito larvae, flatworms, swimming beetles, fungi, ciliates, paramecia, protozoans which act as parasites, predatory copepods and spiders are natural enemies to Asian tiger mosquitoes.
ToxorhynchitesToxorhynchites, also known as mosquito hawks or mosquito eaters, are a cosmopolitan genus. The genus includes the largest known species of mosquitoes, but in spite of their alarming appearance, they are among the few kinds of mosquito that do not suck blood...
larvae, a mosquito genus that does not suck blood, feeds upon other mosquito larvae and are often found with tiger mosquito larvae. Flatworms and also small swimming beetles are considered natural predators.
Fungal relatives of
Oomycetes, also known as water molds from the genus
Coelomomyces (Phylum
ChytridiomycotaChytridiomycota is a division of the Fungi kingdom. The name is derived from the Greek chytridion, meaning "little pot", describing the structure containing unreleased spores. In older classifications, chytrids were placed in the Class Phycomycetes under the subdivision Myxomycophyta of the...
, Order Blastocladiales), develop inside the visceral cavity of mosquito larvae. The species
Coelomomyces stegomyiae was first found on the Asian tiger mosquito.
ParameciaParamecium is a group of unicellular ciliate protozoa, which are commonly studied as a representative of the ciliate group, and range from about 0.05 to 0.35 mm in length. Simple cilia cover the body, which allow the cell to move with a synchronous motion at speeds of approximately 12 body...
, or ciliates, can also affect
Aedes albopictus larvae, and the first detected species was
Lambornella stegomyiae (Hymenostomatida: Tetrahymenidae). The virulence, mortality rate, and subsequent possibilities of
Lambornella being implemented as a biological remedy to control
Aedes albopictus, however, has conflicting views.
Sporozoans of the genus
Ascogregarina (Lecudinidae) infect the larval stage of mosquitoes. The species
Ascogregarina taiwanensis was found in Asian tiger mosquitoes. When the adult mosquitoes emerge from their pupal case, they leave the infectious intermediary stage of parasites in the water and close off the infection cycle. Infected adults are generally smaller than non-infected adults and have an insignificantly higher mortality rate; therefore, food supply and larval density apparently play a role. In competitive situations, an infection with sporozoans can also reduce the biological fitness of other non-infected mosquitoes. However, the use of the parasites as an effective biological remedy to control mosquito populations is implausible because it is essential that the host reaches the adult stage for the transmission of the parasites.
Though they do not commonly occur in the natural habitats of Asian tiger mosquitoes, predatory copepods from the
Cyclopidae family seem to willingly feed on them given the opportunity. Relatives of different genera could therefore present an interesting possibility in the control of tiger mosquitoes.
Predators of adult
Aedes albopictus in Malaysia include various
spiderSpiders are air-breathing arthropods that have eight legs, and chelicerae with fangs that inject venom. They are the largest order of arachnids and rank seventh in total species diversity among all other groups of organisms...
species. Up to 90% of the gathered spiders from rubber plantations and a cemetery fed upon Asian tiger mosquitoes. Whether the spiders would have an effect on the mosquito population is still unclear. Tiger mosquitoes were abundantly present despite the existence of the spiders.
Climatic adaptations
Although
Aedes albopictus is native to tropical and subtropical regions, they are successfully adapting themselves to cooler regions. In the warm and humid tropical regions, they are active the entire? year long; however, in temperate regions they hibernate over winter. Eggs from strains in the temperate zones are more tolerant to the cold than ones from warmer regions. They can even tolerate snow and temperatures under freezing. In addition, adult tiger mosquitoes can survive throughout winter in suitable microhabitats.
Invasive species
The Asian tiger mosquito originally came from Southeast
AsiaAsia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...
. In 1966, parts of Asia and the island worlds of India and the Pacific Ocean were denoted as the area of circulation for the Asian tiger mosquito. Since then, it has spread to Europe, the Americas, the Caribbean, Africa and the Middle East.
Aedes albopictus is one of the 100 world's worst
invasive species"Invasive species", or invasive exotics, is a nomenclature term and categorization phrase used for flora and fauna, and for specific restoration-preservation processes in native habitats, with several definitions....
according to the Global Invasive Species Database.
The
Aedes albopictus mosquito is not native to
AustraliaAustralia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
and
New ZealandNew Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...
. In fact, the species was introduced there multiple times, but has yet to establish itself. This is due to the well organized entomological surveillance programs in the harbors and airports of these countries. Nevertheless, on the islands in the
Torres StraitThe Torres Strait is a body of water which lies between Australia and the Melanesian island of New Guinea. It is approximately wide at its narrowest extent. To the south is Cape York Peninsula, the northernmost continental extremity of the Australian state of Queensland...
between Queensland, Australia and New Guinea
Aedes albopictus has become domestic.
In
EuropeEurope is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
the Asian tiger mosquito first emerged in
AlbaniaAlbania , officially known as the Republic of Albania , is a country in Southeastern Europe, in the Balkans region. It is bordered by Montenegro to the northwest, Kosovo to the northeast, the Republic of Macedonia to the east and Greece to the south and southeast. It has a coast on the Adriatic Sea...
in 1979, where they were evidently introduced through a shipment of goods from
ChinaChinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...
. In 1990-1991, they were most likely brought to
ItalyItaly , officially the Italian Republic languages]] under the European Charter for Regional or Minority Languages. In each of these, Italy's official name is as follows:;;;;;;;;), is a unitary parliamentary republic in South-Central Europe. To the north it borders France, Switzerland, Austria and...
in used tires from Georgia (USA), and since then have spread throughout the entire mainland of
ItalyItaly , officially the Italian Republic languages]] under the European Charter for Regional or Minority Languages. In each of these, Italy's official name is as follows:;;;;;;;;), is a unitary parliamentary republic in South-Central Europe. To the north it borders France, Switzerland, Austria and...
as well as parts of
SicilySicily is a region of Italy, and is the largest island in the Mediterranean Sea. Along with the surrounding minor islands, it constitutes an autonomous region of Italy, the Regione Autonoma Siciliana Sicily has a rich and unique culture, especially with regard to the arts, music, literature,...
and
SardiniaSardinia is the second-largest island in the Mediterranean Sea . It is an autonomous region of Italy, and the nearest land masses are the French island of Corsica, the Italian Peninsula, Sicily, Tunisia and the Spanish Balearic Islands.The name Sardinia is from the pre-Roman noun *sard[],...
. Since 1999, they have established themselves on the mainland of
FranceThe French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...
, primarily southern France. In 2002, they were also discovered in a vacation town on the island of
CorsicaCorsica is an island in the Mediterranean Sea. It is located west of Italy, southeast of the French mainland, and north of the island of Sardinia....
, but did not completely establish themselves there until 2005. In
BelgiumBelgium , officially the Kingdom of Belgium, is a federal state in Western Europe. It is a founding member of the European Union and hosts the EU's headquarters, and those of several other major international organisations such as NATO.Belgium is also a member of, or affiliated to, many...
, they were first detected in 2000, 2001 in
MontenegroMontenegro Montenegrin: Crna Gora Црна Гора , meaning "Black Mountain") is a country located in Southeastern Europe. It has a coast on the Adriatic Sea to the south-west and is bordered by Croatia to the west, Bosnia and Herzegovina to the northwest, Serbia to the northeast and Albania to the...
, 2003 in Canton Ticino in southern
SwitzerlandSwitzerland name of one of the Swiss cantons. ; ; ; or ), in its full name the Swiss Confederation , is a federal republic consisting of 26 cantons, with Bern as the seat of the federal authorities. The country is situated in Western Europe,Or Central Europe depending on the definition....
and
GreeceGreece , officially the Hellenic Republic , and historically Hellas or the Republic of Greece in English, is a country in southeastern Europe....
, 2004 in
SpainSpain , officially the Kingdom of Spain languages]] under the European Charter for Regional or Minority Languages. In each of these, Spain's official name is as follows:;;;;;;), is a country and member state of the European Union located in southwestern Europe on the Iberian Peninsula...
and
CroatiaCroatia , officially the Republic of Croatia , is a unitary democratic parliamentary republic in Europe at the crossroads of the Mitteleuropa, the Balkans, and the Mediterranean. Its capital and largest city is Zagreb. The country is divided into 20 counties and the city of Zagreb. Croatia covers ...
, 2005 in the
NetherlandsThe Netherlands is a constituent country of the Kingdom of the Netherlands, located mainly in North-West Europe and with several islands in the Caribbean. Mainland Netherlands borders the North Sea to the north and west, Belgium to the south, and Germany to the east, and shares maritime borders...
and
SloveniaSlovenia , officially the Republic of Slovenia , is a country in Central and Southeastern Europe touching the Alps and bordering the Mediterranean. Slovenia borders Italy to the west, Croatia to the south and east, Hungary to the northeast, and Austria to the north, and also has a small portion of...
, and 2006 in
Bosnia and HerzegovinaBosnia and Herzegovina , sometimes called Bosnia-Herzegovina or simply Bosnia, is a country in Southern Europe, on the Balkan Peninsula. Bordered by Croatia to the north, west and south, Serbia to the east, and Montenegro to the southeast, Bosnia and Herzegovina is almost landlocked, except for the...
. In the fall of 2007, the first tiger mosquito eggs were discovered in
RastattRastatt is a city and baroque residence in the District of Rastatt, Baden-Württemberg, Germany. It is located on the Murg river, above its junction with the Rhine and has a population of around 50'000...
(Baden-Wuerttemberg,
GermanyGermany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...
). Shortly before, they were found in the northern Alps of Switzerland in Canton Aargau. Two were sighted in the UK during the summer of 2007, as reported by the
Mail OnlineMail Online is the name of the website of the Daily Mail, a newspaper in the United Kingdom. It contains almost all the stories from the Daily Mail and includes a large archive of main stories...
. (Link is in discussion area under topic name "Asian tiger in the UK?"). It has also been sighted in
MaltaMalta , officially known as the Republic of Malta , is a Southern European country consisting of an archipelago situated in the centre of the Mediterranean, south of Sicily, east of Tunisia and north of Libya, with Gibraltar to the west and Alexandria to the east.Malta covers just over in...
during the summers of 2010 and 2011.
Asian tiger mosquitoes were first found in North America in a shipment of used
tireA tire or tyre is a ring-shaped covering that fits around a wheel rim to protect it and enable better vehicle performance by providing a flexible cushion that absorbs shock while keeping the wheel in close contact with the ground...
s at the port of Houston in 1985. Since then they have spread across southern USA, and as far up the East Coast as Maine. This species is an
introduced speciesAn introduced species — or neozoon, alien, exotic, non-indigenous, or non-native species, or simply an introduction, is a species living outside its indigenous or native distributional range, and has arrived in an ecosystem or plant community by human activity, either deliberate or accidental...
in
HawaiiHawaii is the newest of the 50 U.S. states , and is the only U.S. state made up entirely of islands. It is the northernmost island group in Polynesia, occupying most of an archipelago in the central Pacific Ocean, southwest of the continental United States, southeast of Japan, and northeast of...
as well, but has been there since before 1986.
In 1986, the Asian tiger mosquito was discovered in
BrazilBrazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...
and in 1988 in
ArgentinaArgentina , officially the Argentine Republic , is the second largest country in South America by land area, after Brazil. It is constituted as a federation of 23 provinces and an autonomous city, Buenos Aires...
and
MexicoThe United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
, as well. Other parts of
Latin AmericaLatin America is a region of the Americas where Romance languages – particularly Spanish and Portuguese, and variably French – are primarily spoken. Latin America has an area of approximately 21,069,500 km² , almost 3.9% of the Earth's surface or 14.1% of its land surface area...
where the Asian tiger mosquito was discovered are the
Dominican RepublicThe Dominican Republic is a nation on the island of La Hispaniola, part of the Greater Antilles archipelago in the Caribbean region. The western third of the island is occupied by the nation of Haiti, making Hispaniola one of two Caribbean islands that are shared by two countries...
in 1993,
BoliviaBolivia officially known as Plurinational State of Bolivia , is a landlocked country in central South America. It is the poorest country in South America...
,
CubaThe Republic of Cuba is an island nation in the Caribbean. The nation of Cuba consists of the main island of Cuba, the Isla de la Juventud, and several archipelagos. Havana is the largest city in Cuba and the country's capital. Santiago de Cuba is the second largest city...
,
HondurasHonduras is a republic in Central America. It was previously known as Spanish Honduras to differentiate it from British Honduras, which became the modern-day state of Belize...
, and
GuatemalaGuatemala is a country in Central America bordered by Mexico to the north and west, the Pacific Ocean to the southwest, Belize to the northeast, the Caribbean to the east, and Honduras and El Salvador to the southeast...
in 1995,
El SalvadorEl Salvador or simply Salvador is the smallest and the most densely populated country in Central America. The country's capital city and largest city is San Salvador; Santa Ana and San Miguel are also important cultural and commercial centers in the country and in all of Central America...
in 1996,
ParaguayParaguay , officially the Republic of Paraguay , is a landlocked country in South America. It is bordered by Argentina to the south and southwest, Brazil to the east and northeast, and Bolivia to the northwest. Paraguay lies on both banks of the Paraguay River, which runs through the center of the...
in 1999,
PanamaPanama , officially the Republic of Panama , is the southernmost country of Central America. Situated on the isthmus connecting North and South America, it is bordered by Costa Rica to the northwest, Colombia to the southeast, the Caribbean Sea to the north and the Pacific Ocean to the south. The...
in 2002, and
UruguayUruguay ,officially the Oriental Republic of Uruguay,sometimes the Eastern Republic of Uruguay; ) is a country in the southeastern part of South America. It is home to some 3.5 million people, of whom 1.8 million live in the capital Montevideo and its metropolitan area...
and
NicaraguaNicaragua is the largest country in the Central American American isthmus, bordered by Honduras to the north and Costa Rica to the south. The country is situated between 11 and 14 degrees north of the Equator in the Northern Hemisphere, which places it entirely within the tropics. The Pacific Ocean...
in 2003.
In
South AfricaThe Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...
, the species was detected in 1990. In
NigeriaNigeria , officially the Federal Republic of Nigeria, is a federal constitutional republic comprising 36 states and its Federal Capital Territory, Abuja. The country is located in West Africa and shares land borders with the Republic of Benin in the west, Chad and Cameroon in the east, and Niger in...
it has been domestic since at least 1991. It spread to
CameroonCameroon, officially the Republic of Cameroon , is a country in west Central Africa. It is bordered by Nigeria to the west; Chad to the northeast; the Central African Republic to the east; and Equatorial Guinea, Gabon, and the Republic of the Congo to the south. Cameroon's coastline lies on the...
in 1999/2000, to the Bioko Island of Equatorial Guinea in 2001, and to Gabon in 2006.
In the Middle East, the species was detected in the
LebanonLebanon , officially the Republic of LebanonRepublic of Lebanon is the most common term used by Lebanese government agencies. The term Lebanese Republic, a literal translation of the official Arabic and French names that is not used in today's world. Arabic is the most common language spoken among...
in 2003 in
SyriaSyria , officially the Syrian Arab Republic , is a country in Western Asia, bordering Lebanon and the Mediterranean Sea to the West, Turkey to the north, Iraq to the east, Jordan to the south, and Israel to the southwest....
in 2005; the first record in
IsraelThe State of Israel is a parliamentary republic located in the Middle East, along the eastern shore of the Mediterranean Sea...
was published in 2003.
Competition with established species
Aedes albopictus can outcompete and even eradicate other species with similar breeding habitats from the very start of its dispersal to other regions and biotopes. In
KolkataKolkata , formerly known as Calcutta, is the capital of the Indian state of West Bengal. Located on the east bank of the Hooghly River, it was the commercial capital of East India...
, for example, it was observed in the 1960s that egg depositing containers were being settled by the Asian tiger mosquito in city districts where the malaria mosquito (genus
Anopheles) and yellow fever mosquito (
Aedes aegypti) had both been eliminated by the application of
DDTDDT is one of the most well-known synthetic insecticides. It is a chemical with a long, unique, and controversial history....
. The reason why, in this case, may be due to the fact that primarily the inner walls of the houses were treated with DDT to kill the mosquitoes resting there and fight the malaria mosquito. The yellow fever mosquito also lingers particularly in the inside of buildings and would have been also affected. The Asian tiger mosquito rests in the vicinity of human dwellings would therefore have an advantage over the other two species. In other cases, where the yellow fever mosquito was repressed by the Asian tiger mosquito, for instance in Florida, this explanation does not fit. Other hypotheses include competition in the larval breeding waters, differences in metabolism and reproductive biology, or a major susceptibility to sporozoans (
Apicomplexa).
Another species, which was suppressed by the migrating
Aedes albopictus was
Aedes guamensis in
GuamGuam is an organized, unincorporated territory of the United States located in the western Pacific Ocean. It is one of five U.S. territories with an established civilian government. Guam is listed as one of 16 Non-Self-Governing Territories by the Special Committee on Decolonization of the United...
.
The Asian tiger mosquito is similar, in terms of their close socialization with humans, to the common house mosquito (
Culex pipiensCulex pipiens is a species of blood-feeding mosquito of the family Culicidae. It is a vector of some diseases, such as Japanese encephalitis, meningitis, Urticaria...
). Among other differences in their biology,
Culex pipiens prefers larger breeding waters and is more tolerant to cold. In this respect, there is probably not any significant competition or suppression between the two species.
A possible competition among mosquito species that all lay their eggs in knotholes and other similar places (
Aedes cretinus,
Aedes geniculatus and
Anopheles plumbeus) has yet to be observed.
In Europe, the Asian tiger mosquito apparently covers an extensive new niche. This means that there are no native, long-established species that conflict with the dispersal of
Aedes albopictus.
Role as disease vectors
It is known that
Aedes albopictus can transmit pathogens and viruses, such as the West Nile virus, Yellow fever virus, St. Louis encephalitis, dengue fever, and Chikungunya fever.
The Asian tiger mosquito was responsible for the Chikungunya epidemic on the French Island
La RéunionLa Reunion may refer to:* La Reunion , a communal settlement near present-day Dallas, Texas*La Réunion, Lot-et-Garonne, a town in the Lot-et-Garonne department of France*Réunion, an island in the Indian Ocean east of Madagascar...
in 2005-2006. By September 2006, there were an estimated 266,000 people infected with the virus, and 248 fatalities on the island. The Asian tiger mosquito was also the transmitter of the virus in the first and only outbreak of Chikungunya fever on the European continent. This outbreak occurred in the Italian province of
RavennaRavenna is the capital city of the Province of Ravenna in the Emilia-Romagna region of Italy and the second largest comune in Italy by land area, although, at , it is little more than half the size of the largest comune, Rome...
in the summer of 2007, and infected over 200 people. Evidently, mutated strains of the Chikungunya virus are being directly transmitted through
Aedes albopictus particularly well and in such a way that another dispersal of the disease in regions with the Asian tiger mosquito is feared.
The tiger mosquito is also relevant to veterinary medicine. For example, tiger mosquitoes are transmitters of
Dirofilaria immitis, a parasitic round worm that causes
heartwormHeartworm is a parasitic roundworm that is spread from host to host through the bites of mosquitoes. The heartworm is a type of filaria, a small thread-like worm. The definitive host is the dog but it can also infect cats, wolves, coyotes, foxes and other animals, such as ferrets, sea lions and...
in dogs and cats.
Control and suppression
Aedes albopictus has proven to be very difficult to suppress or to control due to their remarkable ability to adapt to various environments, their close contact with humans, and their reproductive biology.
Efficient monitoring or surveillance is essential to prevent the spread and establishment of the species. In addition to the monitoring of ports, warehouses with imported plants, and stockpiles of tires, rest areas on highways and train stations should be monitored with appropriate methods.
The control of the Asian tiger mosquitoes begins with destroying the places where they lay their eggs, which are never far from where people are being bitten, since they are weak fliers, with only about a 200-yard lifetime flying radius. Locate puddles that last more than three days, sagging or plugged roof gutters, old tires holding water, litter, bird baths, inlets to sewers and drainage systems holding stagnant water and any other possible containers or pools of standing water. Flower pots, standing flower vases, knotholes and other crevices that can collect water should be filled with sand or fine gravel to prevent mosquitoes from laying their eggs in them. Litter can also hold rain water and should be removed.
Any standing water in pools, catchment basins, etc., that cannot be drained, or dumped, can be periodically treated with properly labeled insecticides or
Bacillus thuringiensis israelensisBacillus thuringiensis serovar israelensis is a group of bacteria used as biological control agents for larvae stages of certain Dipterans. Bti produces toxins which are effective in killing various species of mosquitoes, fungus gnats, and blackflies, while having almost no effect on other...
(Bti), often formed into doughnut shaped "mosquito dunks". Bti is a bacterium that produces toxins which are effective in killing larvae of mosquitoes and certain other
DipteraDiptera , or true flies, is the order of insects possessing only a single pair of wings on the mesothorax; the metathorax bears a pair of drumstick like structures called the halteres, the remnants of the hind wings. It is a large order, containing an estimated 240,000 species, although under half...
ns, while having almost no effect on other organisms. Bti preparations are readily available at farm, garden, and pool suppliers.
Flowing water will not be a breeding spot, and water that contains
minnowMinnow is a general term used to refer to small freshwater and saltwater fish, especially those used as bait fish or for fishing bait. More specifically, it refers to small freshwater fish of the carp family.-True minnows:...
s is not usually a problem, because the
fishFish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...
eat the mosquito
larvaA 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...
e.
DragonfliesA dragonfly is a winged insect belonging to the order Odonata, the suborder Epiprocta or, in the strict sense, the infraorder Anisoptera . It is characterized by large multifaceted eyes, two pairs of strong transparent wings, and an elongated body...
are also an excellent method of imposing control. Dragonfly larvae eat mosquito larvae in the water, and adults will snatch adult mosquitoes as they fly.
In any case, an efficient surveillance is essential to monitor the presence of tiger mosquitoes and the effect of control programs. So-called ovitraps are normally used for the monitoring of
Aedes albopictus. They are black water containers with floating Styrofoam blocks or small wooden paddles that are in contact with the surface of the water. Female tiger mosquitoes lay their eggs on these surfaces. Through the identification of these eggs or of the larvae that hatch from these eggs in the laboratory, the presence and abundance of mosquito species can be estimated. Versions of these traps with an adhesive film (sticky traps) that catch the egg depositing mosquitoes make the analysis much easier and quicker, but are more complicated in terms of handling. The results of ovitraps are often variable and depend on the availability of alternative egg depositing waters. Due to this, it is best to use them in large numbers and in conjunction with other monitoring methods.
To date, there are few effective traps for the adult Asian tiger mosquito. Those traps that catch other species of mosquitoes do not catch tiger mosquitoes efficiently. A new trap type has now been shown to catch significant numbers of
Aedes albopictus. This device, with the help of a ventilator, produces an upward air current of
ammoniaAmmonia is a compound of nitrogen and hydrogen with the formula . It is a colourless gas with a characteristic pungent odour. Ammonia contributes significantly to the nutritional needs of terrestrial organisms by serving as a precursor to food and fertilizers. Ammonia, either directly or...
,
fatty acidIn chemistry, especially biochemistry, a fatty acid is a carboxylic acid with a long unbranched aliphatic tail , which is either saturated or unsaturated. Most naturally occurring fatty acids have a chain of an even number of carbon atoms, from 4 to 28. Fatty acids are usually derived from...
s, and
lactic acidLactic acid, also known as milk acid, is a chemical compound that plays a role in various biochemical processes and was first isolated in 1780 by the Swedish chemist Carl Wilhelm Scheele. Lactic acid is a carboxylic acid with the chemical formula C3H6O3...
s that takes a similar form and smell of a human body. With the addition of
carbon dioxideCarbon dioxide is a naturally occurring chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom...
, the efficacy of the trap is increased. This means there is a suitable tool available for trapping adult tiger mosquitoes and, for example, examining the existence of viruses in the trapped mosquitoes. Previously, the mosquitoes had to be collected from volunteers to be studied, which is ethically questionable, especially during epidemics. Recent research also indicates this trap type may also have a use as a control tool; in a study in Cesena, Italy, the amount of biting tiger mosquitoes was reduced in places where traps were installed.
Further reading
- Anosike, Jude C.; Nwoke, Bertram E.; Okere, Anthony N.; Oku, Ene E.; Asor, Joe E.; Emmy-Egbe, Ifeyinwa O. & Adimike, Desmond A. (2007): Epidemiology of tree-hole breeding mosquitoes in the tropical rainforest of Imo State, south-east Nigeria. Annals of Agricultural and Environmental Medicine 14 (1): 31–38. PDF fulltext
- Centers for Disease Control and Prevention
The Centers for Disease Control and Prevention are a United States federal agency under the Department of Health and Human Services headquartered in Druid Hills, unincorporated DeKalb County, Georgia, in Greater Atlanta...
(CDC) (2007): Information on Aedes albopictus. Version of November 7, 2005. Retrieved October 31, 2007.
- European Centre for Disease Prevention and Control
The European Centre for Disease Prevention and Control is an independent agency of the European Union aimed at strengthening Europe's defences against infectious diseases. It was established in 2005 and is located in Solna, Sweden....
(ECDC) (2007): Mission Report – Chikungunya in Italy, 17–21.09.2007. PDF fulltext
- Nishida, G. M. & Tenorio, J. M. (1993): What Bit Me? Identifying Hawaiʻi's Stinging and Biting Insects and Their Kin. University of Hawaiʻi Press, Honolulu.
External links
- Tiger mosquitos in Italy
- Asian Tiger Mosquito Information
- Tiger mosquitoes in Spain
- Asian tiger mosquito on the University of Florida
The 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...
/ Institute 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...
Featured Creatures website
- CISR: Asian Tiger Mosquito Center for Invasive Species Research page on Asian tiger mosquito
- Species Profile- Asian Tiger Mosquito (Aedes albopictus), National Invasive Species Information Center, United States National Agricultural Library
The United States National Agricultural Library is one of the world's largest agricultural research libraries, and serves as a National Library of the United States and as the library of the United States Department of Agriculture...
. Lists general information and resources for Asian Tiger Mosquito.