Aedes aegypti (/ˈiːdiːz/ from Greek αηδής: "hateful" and /aɪˈdʒɛpti/ from Latin, meaning "of Egypt"), the yellow fever mosquito, is a mosquito that can spread dengue fever, chikungunya, Zika fever, Mayaro and yellow fever viruses, and other disease agents. The mosquito can be recognized by black and white markings on its legs and a marking in the form of a lyre on the upper surface of its thorax. This mosquito originated in Africa, but is now found in tropical, subtropical and temperate regions throughout the world.
Aedes aegypti originated in Africa and was spread to the New World through slave trade, but is now found in tropical, subtropical and temperate regions throughout the world.Ae. aegypti's distribution has increased in the past two to three decades worldwide, and it is considered to be among the most widespread mosquito species.
In 2016, Zika virus-capable mosquito populations have been found adapting for persistence in warm temperate climates. Such a population has been identified to exist in parts of Washington, DC, and genetic evidence suggests they survived at least the last four winters in the region. One of the study researchers noted, "...some mosquito species are finding ways to survive in normally restrictive environments by taking advantage of underground refugia".As the world's climate becomes warmer, the range of Aedes aegypti and a hardier species originating in Asia, the tiger mosquito Aedes albopictus, which can expand its range to relatively cooler climates, will inexorably spread north and south. Sadie Ryan of the University of Florida was the lead author in a 2019 study that estimated the vulnerability of naïve populations in geographic regions that currently do not harbor vectors i.e., for Zika in the Old World. Ryan's co-author, Georgetown University's Colin Carlson remarked,"Plain and simple, climate change is going to kill a lot of people." As of 2020, the Northern Territory Government Australia and the Darwin City Council have recommended tropical cities initiate rectification programs to rid their cities of potential mosquito breeding stormwater sumps. A 2019 study found that accelerating urbanization and human movement would also contribute to the spread of Aedes mosquitoes.
In continental Europe, Aedes aegypti is not established but it has been found in localities close to Europe such as the Asian part of Turkey. However, a single adult female specimen was found in Marseille (Southern France) in 2018. On the basis of a genetic study and an analysis of the movements of commercial ships, the origin of the specimen could be traced as coming from Cameroon, in Central Africa.
Aedes aegypti is a.mw-parser-output.frac{white-space:nowrap}.mw-parser-output.frac.num,.mw-parser-output.frac.den{font-size:80%;line-height:0;vertical-align:super}.mw-parser-output.frac.den{vertical-align:sub}.mw-parser-output.sr-only{border:0;clip:rect(0,0,0,0);clip-path:polygon(0px 0px,0px 0px,0px 0px);height:1px;margin:-1px;overflow:hidden;padding:0;position:absolute;width:1px}4–7 millimetres (5⁄32–35⁄128 in) long, dark mosquito which can be recognized by white markings on its legs and a marking in the form of a lyre on the upper surface of its thorax. Females are larger than males. Microscopically females possess small palps tipped with silver or white scales, and their antennae have sparse short hairs, whereas those of males are feathery. Aedes aegypti can be confused with Aedes albopictus without a magnifying glass: the latter have a white stripe on the top of the mid thorax.
Males live off fruit and only the female bites for blood, which she needs to mature her eggs. To find a host, she is attracted to chemical compounds emitted by mammals, including ammonia, carbon dioxide, lactic acid, and octenol. Scientists at The United States Department of Agriculture (USDA) Agricultural Research Service studied the specific chemical structure of octenol to better understand why this chemical attracts the mosquito to its host and found the mosquito has a preference for "right-handed" (dextrorotatory) octenol molecules. The preference for biting humans is dependent on expression of the odorant receptor AaegOr4.The white eggs are laid separately into water and not together, unlike most other mosquitoes, and soon turn black. The larvae feed on bacteria, grow over a period of weeks until they reach the pupa stage.
The lifespan of an adult Ae. aegypti is two to four weeks depending on conditions, but the eggs can be viable for over a year in a dry state, which allows the mosquito to re-emerge after a cold winter or dry spell.
