''Anopheles walkeri'' is a species of

mosquito Mosquitoes (or mosquitos) are members of a group of almost 3,600 species of small flies within the family Culicidae (from the Latin ''culex'' meaning " gnat"). The word "mosquito" (formed by ''mosca'' and diminutive ''-ito'') is Spanish for "li ...

found predominantly throughout the

Mississippi River Valley The Mississippi embayment is a physiographic feature in the south-central United States, part of the Mississippi Alluvial Plain. It is essentially a northward continuation of the fluvial sediments of the Mississippi River Delta to its conflue ...

, with its

habitat In ecology, the term habitat summarises the array of resources, physical and biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species habitat can be seen as the physical ...

ranging as far north as southern

Quebec Quebec ( ; )According to the Canadian government, ''Québec'' (with the acute accent) is the official name in Canadian French and ''Quebec'' (without the accent) is the province's official name in Canadian English is one of the thirtee ...

Canada Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by tot ...

. The eggs of ''A. walkeri'' are laid directly on the water surface in freshwater swamp habitats. Since its eggs are not resistant to desiccation, this species is restricted to swampy regions with plenty of water. ''Anopheles walkeri'', as with many other anophelines, begins to become active later in the evening than most other mosquito species in its range. This species becomes especially active late at night when in search of a blood meal. Feeding activity is affected greatly by environmental conditions within its

microclimate A microclimate (or micro-climate) is a local set of atmospheric conditions that differ from those in the surrounding areas, often with a slight difference but sometimes with a substantial one. The term may refer to areas as small as a few squ ...

. Wind, low humidity and cool temperatures (around and below), are all negatively correlated with feeding aggression.

Life cycle

''Anopheles walkeri'' has a

multivoltine Voltinism is a term used in biology to indicate the number of broods or generations of an organism in a year. The term is most often applied to insects, and is particularly in use in sericulture, where silkworm varieties vary in their voltinism. ...

life cycle Life cycle, life-cycle, or lifecycle may refer to: Science and academia *Biological life cycle, the sequence of life stages that an organism undergoes from birth to reproduction ending with the production of the offspring * Life-cycle hypothesis ...

. It produces a hardy winter egg which differs morphologically from the more vulnerable summer eggs by having enlarged floats on the

dorsal Dorsal (from Latin ''dorsum'' ‘back’) may refer to: * Dorsal (anatomy), an anatomical term of location referring to the back or upper side of an organism or parts of an organism * Dorsal, positioned on top of an aircraft's fuselage * Dorsal c ...

side. By overwintering in egg form, this species is able to mature through one full larval generation before hibernating adults of other species are able to become active. The multivoltine life cycle means this species is active during both the swampy, open water conditions of early spring, as well as later in the year after the swampland has become thickened with plant growth. It takes about 10 days to mature through the larval stages and

pupate A pupa ( la, pupa, "doll"; plural: ''pupae'') is the life stage of some insects undergoing transformation between immature and mature stages. Insects that go through a pupal stage are holometabolous: they go through four distinct stages in their ...

, dependent on temperature and water conditions. Adults will typically mate within a few hours of emergence from their pupated form. The females then begin to seek out a blood meal to provide necessary

protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, res ...

to facilitate egg development. The female will then rest while the eggs develop. Once mature, the eggs are oviposited and the female begins the process all over again, feeding and laying for the 40 days or so that it lives for.

Epidemiology

Due to

preferences, coupled with particularly low rates of virus detection, ''Anopheles walkeri'' is considered to be an unlikely

vector Vector most often refers to: *Euclidean vector, a quantity with a magnitude and a direction *Vector (epidemiology), an agent that carries and transmits an infectious pathogen into another living organism Vector may also refer to: Mathematic ...

West Nile virus West Nile virus (WNV) is a single-stranded RNA virus that causes West Nile fever. It is a member of the family '' Flaviviridae'', from the genus '' Flavivirus'', which also contains the Zika virus, dengue virus, and yellow fever virus. The v ...

humans Humans (''Homo sapiens'') are the most abundant and widespread species of primate, characterized by bipedalism and exceptional cognitive skills due to a large and complex brain. This has enabled the development of advanced tools, culture, ...

. In addition, it has not been shown to demonstrate any capacity of transmitting

avian malaria Avian malaria is a parasitic disease of birds, caused by parasite species belonging to the genera '' Plasmodium'' and '' Hemoproteus'' (phylum Apicomplexa, class Haemosporidia, family Plasmoiidae). The disease is transmitted by a dipteran vecto ...

(''Plasmodium circumflexum'' and ''P. polare''). However, specimens of ''A. walkeri'' in the

southern United States The Southern United States (sometimes Dixie, also referred to as the Southern States, the American South, the Southland, or simply the South) is a geographic and cultural region of the United States of America. It is between the Atlantic Ocean ...

have been shown to harbor the human infecting strains of

malaria Malaria is a mosquito-borne infectious disease that affects humans and other animals. Malaria causes symptoms that typically include fever, tiredness, vomiting, and headaches. In severe cases, it can cause jaundice, seizures, coma, or death. S ...

, ''Plasmodium vivax'' and ''P. falciparum'', albeit infrequently (freq= <0.005).

References

{{Taxonbar, from=Q4770083 walkeri Diptera of North America Insects described in 1901 Taxa named by Frederick Vincent Theobald