Aedes (Stegomyia) aegypti (Linnaeus, 1762)
Common name: yellow fever mosquito
New Zealand Status: Not Present
Invasive; moderate biosecurity threat. Aedes aegypti is probably endemic to the Afrotropical region, and is now almost cosmopolitan within the 20°C isotherms having been spread by human activities (Belkin 1962). Where it has been introduced it is closely associated with human settlement and is able to breed in artificial containers of all types.
Vector and Disease Information
Aedes aegypti is historically the primary vector for the viruses that cause human dengue and yellow fever. Subtropical and tropical zones of the Americas are still endemic for these diseases. Adults are found within or close-by human environments, often biting indoors or in sheltered areas near the house; biting is predominantly by day in shaded areas but may also occur early in the night. It is a potential vector of dog heartworm, Murray Valley encephalitis and Ross River viruses (Russell 1993). In Asia, this species is also considered the principal vector of chikungunya virus. Past efforts to eradicate this vector from the United States have failed.
Distribution (based on Biogeographic Regions)
Australasian Biogeographic Region
New Zealand
Not present, intercepted.
Intercepted 1950 (Laird 1995), 1999, 2001 (NZ Ministry of Health).
Australia
Present, introduced
Currently known to exist only in Queensland and predominantly northern coastal Queensland, but previously known from Western Australia, Northern Territory, and southern New South Wales (Russell 1993).
Rest of the Region
Cook Islands, Fiji, French Polynesia, New Caledonia, Samoa, Tonga, Vanuatu (Eberhart-Phillips 1999).
Afrotropical Region
Present, endemic
Ghana, Madagascar, Mauritius, Nigeria, Sierra Leone, Sudan West Africa, (White 1980).
Other Biogeographic Regions
Present, introduced
USA
In the eastern United States, Aedes aegypti occurs in Mississippi, Alabama, Georgia, Florida, Tennessee, Kentucky, South Carolina, North Carolina, Virginia, New York, Delaware, Maryland and the District of Columbia. Western states include Arkansas, Illinois, Kansas, Louisiana, Missouri, Oklahoma, New Mexico and Texas. Densities are greatest in the Gulf Coastal states (Womack 1993). Since the introduction of Aedes albopictus to the USA, some populations of Aedes aegypti (especially in Florida) have become seriously diminished, suggesting competetive displacement (Craig 1993).
Brazil, Caribbean, Central America, Cuba, Indonesia, Latin America, Malaysia, Mexico, Nicaragua, Philippines, Singapore, Thailand, Venezuela, Vietnam (Eberhart-Phillips 1999). Originally from Africa, more than 200 years ago spread to almost every community in tropical America and Asia (Eberhart-Phillips 1999). Now worldwide, this species has a cosmopolitan range extending from 40 degrees N to 40 degrees S latitude. It is found throughout most tropical to subtropical world regions. Survival is poor in hot, dry climates.
Taxonomic Position
This species is placed in Group A (aegypti) of the subgenus Stegomyia. Aedes aegypti includes the dark subspecies formosus (Africa south of the Sahara), and two 'domestic' forms. These are the intermediate colour form that is the type species, and the pale Australian variety queenslandensis (Belkin 1962). Adult females may be confused with Ochlerotatus notoscriptus (already introduced to New Zealand) which has a similar scutal pattern but has a pale band in the middle of the proboscis (Russell 1993). A recent suggested change in taxonomy (Reinert & Harbach 2005) has elevated the subgenus Stegomyia to generic level, making the new name for this mosquito Stegomyia aegypti.
Diagnosis
A diagnosis is the minimum set of characters and states that will separate this taxon from all others in this set of taxa.
| Diagnostic characters | State |
| Erect scales of the head | Occiput only |
| Lower mesepimeral setae (one or more) | Present |
| Pale scales of proboscis | Absent |
| Pale scales on the wings | Absent, wings completely dark scaled |
Characteristic Features
FEMALES - A smallish dark mosquito with conspicuous white markings and banded legs. Head: proboscis all black, palps white tipped. Thorax: scutum has a dorsal pattern of white scales in the form of a 'lyre' with curved lateral and 2 central stripes contrasting with a general covering of narrow dark scales, paratergite with a patch of broad white scales. Wings: wings dark scaled. Legs: hind legs femur pale scaled on basal three-quarters with dark scales dorsally on apical two-thirds and ventrally on apical third, tibia dark, tarsi with pale basal bands on 1 - 4 and 5 all pale. Abdomen: tergites with median and lateral white scale patches or bands (possibly some white scales on apical margins), sternites mainly pale scaled with subapical bands on distal segments (Russell 1993).
