The
Asian tiger mosquito or
forest day mosquito (
Aedes (Stegomyia) albopictus), from the
mosquitoMosquito is a common insect in the family 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...
Culicidae, is characterized by its
blackBlack is the color of objects that do not emit or reflect light in any part of the visible spectrum; they absorb all such frequencies of light...
and
white White is a color, the perception which is evoked by light that stimulates all three types of color sensitive cone cells in the human eye in nearly equal amounts and with high brightness compared to the surroundings. A white visual stimulation will be void of hue and grayness.White light can be...
stripeOriginating from the Latin word "stripus"; a stripe is a long, straight region of a single color; it may refer to:* Candystripe, a pattern of diagonal stripes twisted around a cylinder stereotypically embodied by the candy cane...
d
legŁęg may refer to the following places in Poland:*A former name for the town of Ełk *Łęg, Lower Silesian Voivodeship *Łęg, Kuyavian-Pomeranian Voivodeship *Łęg, Łódź Voivodeship...
s, and small black and white
bodyWith regard to living things, a body is the physical body of an individual. "Body" often is used in connection with appearance, health issues and death...
. It is native to the tropical and subtropical areas of
Southeast AsiaManila
Bangkok
Ho Chi Minh City
Kuala Lumpur
Singapore
Yangon
Bandung
Hanoi
Surabaya
Taichung
Kaohsiung
Medan|-|}...
; 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.
Name and systematics
In 1895, 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...
albopictus (
lat.Lat. or lat. is an abbreviation for:*latin*latitude* Lat - a widely-published Malaysian cartoonist....
Culex “gnat, midge” and
albopictus “white embroided”). Later, the species was assigned to the genus
AedesAedes is a genus of mosquito originally found in tropical and subtropical zones, but has spread by human activity to all continents excluding Antarctica. Several of the species transmit important human diseases and one species, Aedes albopictus, is the most invasive mosquito in the world...
(
gr.Ancient Greek is the historical stage in the development of the Greek language spanning across the Archaic , Classical , and Hellenistic periods of ancient Greece and the ancient world. It is predated in the 2nd millennium BC by Mycenaean Greek...
άηδής, "unpleasant" )and referred to as
Aedes albopictus. Like the yellow fever mosquito, it belongs to the subgenus
Stegomyia (gr.
στέγος, "covered, roofed", referring to the scales that completely cover the dorsal surface in this Subgenus, and
μυία, "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 only 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 the form, structure and configuration of an organism.This includes aspects of the outward appearance as well as the form and structure of the internal parts like bones and organs...
very similar. However, as in all mosquito species, the
antennaeAntennae in biology have historically been paired appendages used for sensing in arthropods and crustaceans. More recently, the term has also been applied to cilium structures present in many 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 probiscis is dark colored, the upper surface of the end segment of the palps is covered in silvery scales, and the
labiumLabium is a Latin-derived term meaning "Lip". Labium and its derivatives are used to describe any lip-like structure, but in the English language, labium often specifically refers to parts of the vulva....
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
scutellumThe scutellum is the posterior portion of either the mesonotum or the metanotum of an insect thorax; however, it is used almost exclusively in the former context, as the metanotum is rather reduced in most insect groups. In the Hemiptera, and some Coleoptera, the scutellum is a small triangular...
, 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.The tibia is named for the greek aulos flute, also known as a tibia.-In humans:...
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
proboscisIn general, a proboscis is an elongated appendage from the head of an animal, either a vertebrate or an invertebrate..-Etymology:...
that she uses to collect
bloodBlood is a specialized bodily fluid that delivers necessary substances to the body's cells — such as nutrients and oxygen — and transports 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 the northern continent of the Americas, situated in the Earth's northern hemisphere and in the western hemisphere. It is bordered on the north by the Arctic Ocean, on the east by the North Atlantic Ocean, on the southeast by the Caribbean Sea, and on the west by the North Pacific...
, 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 utilizes similar breeding waters.
Aedes cretinus also has a white stripe on the Scutum, 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, Crete, Greece, Macedonia, Georgia and Turkey.
In Asia, the Asian tiger mosquito can be mistaken for other members of the subgenus
Stegomyia, because they frequently display a similar black and white pattern, particularly, the most prevalent species in the tropics and subtropics, 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 of the form of a lyre on the thorax...
. It can be hard to distinguish
Aedes albopictus from the closely related
Aedes scutellaris (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 with Manila as its capital city. It comprises 7,107 islands in the western Pacific Ocean....
),
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, and the most populous democracy in the world. Bounded by the Indian Ocean on the south, the Arabian Sea on the west, and the Bay of Bengal...
,
IndonesiaThe Republic of Indonesia is a country in Southeast Asia and Oceania. Indonesia comprises 17,508 islands. With an estimated population of around 237 million people, it is the world's fourth most populous country, with the world's largest population of Muslims.Indonesia is a republic, with an...
,
MalaysiaMalaysia is a country in Southeast Asia that consists of thirteen states and three Federal Territories, with a total landmass of . The capital city is Kuala Lumpur, while Putrajaya is the seat of the federal government. The population stands at over 28 million inhabitants...
,
MyanmarBurma, officially the Union of Myanmar, is the largest country by geographical area in mainland Southeast Asia or Indochina. The country is bordered by China on the northeast, Laos on the east, Thailand on the southeast, Bangladesh on the west, India on the northwest and the Bay of Bengal to the...
,
NepalNepal , officially the Federal Democratic Republic of Nepal, is a landlocked country in South Asia and the world's youngest republic. It is 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 as Formosa , is the largest island of the Republic of China in East Asia. Taiwan is located east of the Taiwan Strait, off the southeastern coast of mainland China...
,
ThailandThe Kingdom of Thailand is an independent country that lies in the heart of Southeast Asia.It is bordered to the north by Laos and Burma, to the east by Laos and Cambodia, to the south by the Gulf of Thailand and Malaysia, and to the west by the Andaman Sea and Burma...
, and
VietnamVietnam , 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 to the east...
) 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 receive their energy demand from nectar and other sweet plant juices just as the males do. In regards to
hostHost or hosts may refer to:* Host or sacramental bread* Host — organism harboring another organism on or in itself* Host — "personality" emphasized in treating dissociative identity disorder...
location,
Carbon DioxideCarbon dioxide is a chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom. It is a gas at standard temperature and pressure and exists in Earth's atmosphere in this state...
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 the perception of host stimulants which is then followed by 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 NH
3. It is normally encountered as a gas with a characteristic pungent odor. Ammonia contributes significantly to the nutritional needs of terrestrial organisms by serving as a precursor to foodstuffs and fertilizers...
, and
lactic acidLactic acid , also known as milk acid, is a chemical compound that plays a role in several biochemical processes. It was first isolated in 1780 by a Swedish chemist, Carl Wilhelm Scheele, and is a carboxylic acid with a chemical formula of C
3H
6O
3...
) are the most attractive.
The Asian tiger mosquito particularly bites during the day. 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 microliters μl.
Aedes albopictus also bites other mammals and birds besides humans. 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 koji 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, and...
that can jump species boundaries.
Natural enemies
ToxorhynchitesToxorhynchites, also known as mosquito hawks or mosquito eaters, are a cosmopolitan genus and one of the few kinds of mosquito that do not suck blood. Rather, the adults subsist on nectar and other natural carbohydrates...
larvae, a mosquito genus that does not suck blood, feeds upon other mosquito larvae and are often found together with tiger mosquito larvae. Flatworms and also small swimming beetles are considered natural predators.
Primarily fungi, ciliates, paramecia, and protozoan act as parasites to Asian tiger mosquitoes. Relatives of
Oomycetes, also known as water molds, from the genus
Coelomomyces (
PhylumIn biology, a phylum ["Phylum" is adopted from the Greek phylai, the clan-based voting groups in Greek city-states.] is a taxonomic rank below Kingdom and above Class...
ChytridiomycotaChytridiomycota or chytrids is a division of the Fungi kingdom. The name is derived from the Greek chytridion, meaning "little pot", describing the structure containing unreleased spores...
,
OrderIn scientific classification used in biology, the order is# a taxonomic rank used in the classification of organisms. Other well-known ranks are life, domain, kingdom, phylum, class, family, genus, and species, with order fitting in between class and family...
Blastocladiales) develop inside the visceral cavity of mosquito larvae. The species
Coelomomyces stegomyiae was first found on the Asian tiger mosquito.
ParameciumParamecia, also known as Lady Slippers, due to their appearance, are a group of unicellular ciliate protozoa, which are commonly studied as a representative of the ciliate group, and range from about 50 to 350 μm in length. Simple cilia cover the body, which allow the cell to move with a...
, 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 described 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 roll. In competitive situations, an infection with sporozoans can also reduce the biological fitness of other non-infected mosquitoes. However, the utilization of parasites as an effective biological remedy to control mosquito populations is implausible because it is essential that the host reaches the adult stage in order for the transmission of the parasites.
Even 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 spider 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
Originally, the Asian tiger mosquito comes from Southeast
AsiaAsia is the world's largest and most populous continent, located in the eastern and northern hemispheres. It covers 8.6% of the earth's total surface area and with approximately 4 billion people, it hosts 60% of the world's current human population.Asia is traditionally defined as part of the...
. In 1967 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' is a phrase with several definitions. The first definition expresses the phrase in terms of non-indigenous species that adversely affect the habitats they invade economically, environmentally or ecologically...
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 continental mainland , the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans...
and
New ZealandNew Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses , and numerous smaller islands, most notably Stewart Island/Rakiura and the Chatham Islands. The indigenous Māori named New Zealand Aotearoa, commonly translated as The Land of the Long White Cloud...
. 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 water divide of the Ural Mountains, the Ural River, the Caspian Sea, the Caucasus Mountains , and the Black Sea to the southeast...
the Asian tiger mosquito first emerged in
AlbaniaAlbania , officially the Republic of Albania , is a Mediterranean country in South Eastern Europe. It is bordered by Montenegro to the north, Kosovo to the northeast, Macedonia to the east and Greece to the south-east...
in 1979, where they were evidently introduced through a shipment of goods from
ChinaChina is a cultural region, an ancient civilization, and, depending on perspective, a national or multinational entity extending over a large area in East Asia....
. In 1990/1991, they were most likely brought to
ItalyItaly , officially the Italian Republic , is a country located on the Italian Peninsula in Southern Europe and on the two largest islands in the Mediterranean Sea, Sicily and Sardinia. Italy shares its northern, Alpine boundary with France, Switzerland, Austria and Slovenia...
in used tires from Georgia (USA) and since then have spread throughout the entire mainland of
ItalyItaly , officially the Italian Republic , is a country located on the Italian Peninsula in Southern Europe and on the two largest islands in the Mediterranean Sea, Sicily and Sardinia. Italy shares its northern, Alpine boundary with France, Switzerland, Austria and Slovenia...
as well as parts of
SicilySicily is the largest island in the Mediterranean Sea. It is an autonomous region of Italy. Several much smaller islands surrounding it are considered to be part of Sicily....
and
SardiniaSardinia is the second-largest island in the Mediterranean Sea . The area of Sardinia is . The nearest land masses to the island are the French island of Corsica, the Italian Peninsula, Tunisia, and the Spanish Balearic Islands...
. Since 1999 they have established themselves on the mainland of
FranceFrance , officially the French Republic , is a country located in Western Europe, with several overseas islands and territories located on other continents. Metropolitan France extends from the Mediterranean Sea to the English Channel and the North Sea, and from the Rhine to the Atlantic Ocean...
, primarily southern France. In 2002, they were also discovered in a vacation town on the island of
CorsicaCorsica is the fourth largest 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
BelgiumThe Kingdom of Belgium is a country in northwest Europe. It is a founding member of the European Union and hosts its headquarters, as well as those of other major international organizations, including NATO...
, they were detected for the first time in 2000, 2001 in
MontenegroMontenegro , 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, Kosovo to the east and Albania to the south...
, 2003 in Canton Ticino in southern
SwitzerlandSwitzerland , officially the Swiss Confederation , is a federal republic consisting of 26 states named cantons, with Bern as the seat of the federal authorities...
and
GreeceGreece , officially the Hellenic Republic , is a country in southeastern Europe, situated on the southern end of the Balkan Peninsula....
, 2004 in
SpainSpain , officially the Kingdom of Spain , is a country located in southwestern Europe on the Iberian Peninsula.
[The Spanish constitution does not establish any official denomination of the country, even though España , Estado español and Nación española are used interchangeably...]
and
CroatiaCroatia , officially the Republic of Croatia , is a country in southeast Europe, at the crossroads of the Pannonian Plain, the Balkans, and the Mediterranean Sea. Its capital is Zagreb...
, 2005 in the
NetherlandsThe Netherlands is a country in Northwestern Europe, constituting the major portion of the Kingdom of the Netherlands. It is a parliamentary democratic constitutional monarchy. The Netherlands borders the North Sea to the north and west, Belgium to the south, and Germany to the east...
and
SloveniaSlovenia , officially the Republic of Slovenia , is a country in Central Europe bordering Italy to the west, the Adriatic Sea to the southwest, Croatia to the south and east, Hungary to the northeast, and Austria to the north...
, and 2006 in
Bosnia and HerzegovinaBosnia and Herzegovina Bosnia and Herzegovina Bosnia and Herzegovina ( or (Bosnian, Croatian, Serbian Latin: Bosna i Hercegovina; Serbian Cyrillic: Босна и Херцеговина) is a country in Southeast Europe, on the Balkan Peninsula...
. In the fall of 2007, the first tiger mosquito eggs were discovered in
RastattRastatt is a city in the District of Rastatt, Baden-Württemberg, Germany. It is located on the Murg river, 6 km above its junction with the Rhine and has a population of over 47,000...
(Baden-Wuerttemberg,
GermanyGermany , officially the Federal Republic of Germany , is a country in Central Europe. It is bordered to the north by the North Sea, Denmark, and the Baltic Sea; to the east by Poland and the Czech Republic; to the south by Austria and Switzerland; and to the west by France, Luxembourg, Belgium,...
). Shortly before, they were found in the northern Alps of Switzerland in Canton Aargau.
Asian tiger mosquitoes were first found in North America in a shipment of used
tireA tire is a ring-shaped covering that fits around a wheel 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, alien, exotic, non-indigenous, or non-native species, or simply an introduction, is a species living outside its native distributional range, which has arrived there by human activity, either deliberate or accidental...
in
HawaiiHawaii is the newest of the 50 U.S. states, and is the only state made up entirely of islands. It is located on an archipelago in the central Pacific Ocean, southwest of the continental United States, southeast of Japan, and northeast of Australia. The state was admitted to the Union on August...
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 a country in South America. It is the fifth largest country by geographical area, occupying nearly half of South America, the fifth most populous country, and the fourth most populous democracy in the world. Bounded by the Atlantic Ocean...
and in 1988 in
ArgentinaArgentina, officially the Argentine Republic , is the second largest country in South America, constituted as a federation of 23 provinces and an autonomous city, Buenos Aires. It is the eighth largest country in the world by land area and the largest among Spanish-speaking nations, though Mexico,...
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, Portuguese, and variably French – are primarily spoken. Latin America has an area of approximately 21,069,501 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 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 occupied by two countries...
in 1993,
BoliviaBolivia, officially Plurinational State of Bolivia , is a landlocked country in central South America. It is bordered by Brazil to the north and east, Paraguay and Argentina to the south, and Chile and Peru to the west....
,
CubaThe Republic of Cuba is an island country in the Caribbean. It consists of the 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. Cuba is home to over 11 million people and is...
,
HondurasHonduras is a republic in Central America. It was formerly known as Spanish Honduras to differentiate it from British Honduras...
, 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. Its size is just under 110,000 km² with an estimated population...
in 1995,
El SalvadorEl Salvador is the smallest and most densely populated country in Central America. It borders the Pacific Ocean between Guatemala and Honduras. It lies on the Gulf of Fonseca, as does Nicaragua further south. It has a population of approximately 5.7 million people as of 2009 on...
in 1996,
ParaguayParaguay, officially the Republic of Paraguay , is one of the two landlocked countries which lie entirely within the Western Hemisphere, the other being Bolivia, both in South America....
in 1999,
PanamaPanama, officially the Republic of Panama , is the southernmost country of both Central America and, in turn, North 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...
in 2002, and
UruguayUruguay , is a country located in the southeastern part of South America. It is home to 3.46 million people, of whom 1.1 million live in the capital Montevideo and its metropolitan area. An estimated 88–94% of the population are of mostly European and/or mixed descent.Uruguay's only land border is...
and
NicaraguaNicaragua officially the Republic of Nicaragua , is a representative democratic republic. It is the largest country in Central America with an area of 130,373 km
2. The country is bordered by Honduras to the north and Costa Rica to the south. The Pacific Ocean lies to the west of...
in 2003.
In
South AfricaThe Republic of South Africa is a country located at the southern tip of Africa, with a coastline on the Atlantic and Indian Oceans. To the north lie Namibia, Botswana and Zimbabwe, to the east are Mozambique and Swaziland, while Lesotho is an independent country surrounded by South Africa.Modern...
, the species was detected in 1990. In
NigeriaNigeria , officially the Federal Republic of Nigeria, is a federal constitutional republic comprising thirty-six states and one Federal Capital Territory. 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...
it has been domestic since at least 1991. It spread to
CameroonThe Republic of Cameroon is a unitary republic of central and western 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 Bight of...
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 Lebanon
[Republic of Lebanon is the most common term used by Lebanese government agencies...]
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
IsraelIsrael officially the State of Israel , is a developed state in Western Asia located on the eastern shore of the Mediterranean Sea. It borders Lebanon in the north, Syria in the northeast, Jordan in the east, and Egypt on the southwest, and contains geographically diverse features within its...
was published in 2003.
Means of dispersal
Over large distances the worldwide distribution of
Aedes albopictus is carried out primarily through sea routes, in which the eggs, larvae, and pupae in combination with water-filled used tires, lucky bamboo (
Dracaena sanderiana) and cut flowers are transported around. Alongside sea transport, the transport of mosquitoes in personal vehicles, delivery trucks, and trains plays an important role.
Competition to established species
Aedes albopictus out competing and eradicating other species with similar breeding habitats can be independently observed from the very start of their dispersal to other regions and biotypes.
In
Kolkata, formerly , is the capital of the Indian state of West Bengal. It is located in eastern India on the east bank of the River Hooghly. When referred to as Calcutta, it usually includes the suburbs, and thus its population exceeds 15 million, making it India's third-largest metropolitan area and...
, for example, it was already being observed in the 1950s that in city districts where the malaria mosquito (genus
Anopheles) was fought off with
DDTDDT is one of the most well-known synthetic pesticides. It is a chemical with a long, unique, and controversial history....
there were also no yellow fever mosquitoes (
Aedes aegypti) to be found. Nevertheless, egg depositing containers were being settled by the Asian tiger mosquitoes. 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, for the most part, 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 island in the western Pacific Ocean and is an organized, unincorporated territory of the United States. It is one of five U.S. territories with an established civilian government. The island's capital is Hagåtña...
.
The Asian tiger mosquito is similar, in terms of their close socialization with humans, to the common house mosquito (
Culex pipiens). Among other differences in their biology,
Culex pipiens prefer larger breeding waters and are more tolerant to the 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. These species, however, do not appear to favor human environments.
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 the
Aedes albopictus mosquito.
Role as disease vectors
It is known that
Aedes albopictus can transmit pathogens and viruses, such as, the
West Nile VirusWest Nile virus is a virus of the family Flaviviridae. Part of the koji 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, and...
,
Yellow fever virusYellow fever virus is a flavivirus of the family Flaviviridae. It is a positive sense single-stranded RNA virus.It is the agent of yellow fever....
,
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 and dengue hemorrhagic fever are acute febrile diseases, found in the tropics, and caused by four closely related virus serotypes of the genus Flavivirus, family Flaviviridae. It is also known as breakbone fever...
, and Chikungunya fever to name a few.
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*La Reunión , a 2007 album by reggaeton duo Yaga & Mackie...
in 2005/2006. By September 2006, there was an estimated 266,000 people that were 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 a city and comune in the Emilia-Romagna region of Italy. The city is inland, but is connected to the Adriatic Sea by a canal. Ravenna was the capital of the Western Roman Empire till 476. It was later the capital ofKingdom of the Ostrogoths and the Exarchate of Ravenna till 751...
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 veterinarian medicine. For example, the 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 mosquito begins with destroying the places where they lay their eggs, which are never far from where people are being bitten, since this is a weak flyer, 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 Dipterans, 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
minnow-"True" minnows:Minnow, many of the smaller fish in the subfamily Leuciscinae:* Bluntnose minnows, fish in the genus Pimephales* Cardinal minnows, fish in the genus Tanichthys* Cheat Minnow...
s is not usually a problem, because the
fishA fish is any aquatic vertebrate animal that is typically ectothermic , covered with scales, and equipped with two sets of paired fins and several unpaired fins...
eat the mosquito
larvaA larva is a young form of animal with indirect development, going through or undergoing metamorphosis ....
e.
DragonfliesA dragonfly is a type of 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.
InsecticideAn insecticide is a pesticide used against insects. They include ovicides and larvicides used against the eggs and larvae of insects respectively. Insecticides are used in agriculture, medicine, industry and the household. The use of insecticides is believed to be one of the major factors behind...
application against adult mosquitoes has only a limited effect. Most mosquito spraying done at night will have little effect on Asian tiger mosquitoes, if the resting places are not treated. Daytime spraying may be a violation of label directions if foraging bees are present on blossoms in the application area. More importantly, larvae and the dried eggs are a reservoir from which the mosquito population will usually recover rapidly.
In any case, an efficient surveillance is essential to monitor the presence of tiger mosquitoes and the effect control programs have.
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 NH
3. It is normally encountered as a gas with a characteristic pungent odor. Ammonia contributes significantly to the nutritional needs of terrestrial organisms by serving as a precursor to foodstuffs and fertilizers...
,
fatty acidIn chemistry, especially biochemistry, a fatty acid is a carboxylic acid often with a long unbranched aliphatic tail , which is either saturated or unsaturated...
s, and
lactic acidLactic acid , also known as milk acid, is a chemical compound that plays a role in several biochemical processes. It was first isolated in 1780 by a Swedish chemist, Carl Wilhelm Scheele, and is a carboxylic acid with a chemical formula of C
3H
6O
3...
s that takes a similar form and smell of a human body. With the addition of
carbon dioxideCarbon dioxide is a chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom. It is a gas at standard temperature and pressure and exists in Earth's atmosphere in this state...
, 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 off of volunteers to be studied, which is ethically questionable especially during epidemics. Recent research also indicates that 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 put up.
External links
- Tiger Mosquitos in Italy
- Tiger mosquitoes in Spain
- Asian tiger mosquito on the UF
The University of Florida is a public land-grant, sea-grant, space-grant major research university located on a campus located in Gainesville, Florida, in the United States. The university traces its origins to 1853, and has continuously operated on its present Gainesville campus since the fall...
/ IFASThe 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 Web site
- CISR: Asian Tiger Mosquito Center for Invasive Species Research page on Asian Tiger Mosquito