Most Common Types of Mosquitoes in the US

closeup image of a mosquito on a skin

There are 3,500 species of mosquitoes in the world with 176 of them found in North America. The most common mosquitoes in the U.S. are also the ones that pose the greatest threats to people: the Aedes, Anopheles, and Culex species.

Basic Mosquito Anatomy

graphic showing parts of mosquito

Aedes Species

Aedes mosquitoes have distinctive black and white markings on their bodies. 

picture of a mosquito sitting on a skin
Aedes aegypti
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There are two Aedes species that stand out:

  • Aedes aegypti is known as the yellow fever mosquito. It is brown in color with white bands on its legs. Native to Africa, it has been transmitted to the U.S. and is moving in to urban areas with or without vegetation, indoors and outdoors. Aedes aegypti is found in 23 states.
  • Aedes albopictus, known as the Asian tiger mosquito, is dark in color with white bands  on its legs and a single silver stripe down its back. Native to Southeast Asia, it is spreading across the U.S. in thickets and dense vegetation. 

The name of the species comes from the ancient Greek word for “unpleasant” or “odious.” The name fits, since they are prolific at breeding and irritants to animals, especially humans.

There are 700 species of Aedes in the world: 

  • When does it bite: During the day, unlike most mosquitoes. 
  • What diseases does it pass on: Yellow fever, dengue fever (that was eradicated from the U.S. in the 1950s, then made a comeback), Zika virus, Chikungunya, and lymphatic filariasis. There are 390 million dengue infections in the world every year.
  • What is its need for blood: Adult female mosquitoes need blood to produce eggs. After feeding, female mosquitoes look for water to lay eggs.
  • Does it go after humans: Prefer to live near people, likely so they can feed on them.
  • Where does it lay its eggs: On the inner walls of containers with water. When the water rises, the eggs are moistened and that begins their development. Eggs can live eight months before being moistened. Eggs need as little as ¼-inch of water.
  • Where does it live: Anyplace with standing water, which is allowing it to adapt to urban domestic homes, moving into vases, water tanks, septic tanks, and the like. 
  • Sun or shade for the laying of eggs: In open water in the sun
  • Life cycle of the Aedes: From 10 days to, in cool weather, several months.
  • How far does it spread: In its lifetime, these mosquitoes will only fly within a few blocks.
  • How to fight back: Eliminate places they breed, install or repair netting and screens, use bug repellent, wear long clothing. There are vaccinations for yellow fever, though not the other diseases.

Anopheles Species

mosquito sitting on a skin
Anopheles mosquito
Photo Credit: Henrik_L / Canva Pro / License

The name comes from the ancient Greek word for “useless,” a comment on a species first identified in 1818. Anopheles started on the East Coast and has already spread across the Mississippi as it makes its way west.

There are two Anopheles species that stand out:

  • Anopheles quadrimaculatus, the name used for five related species found mostly in the eastern U.S. These species are very dark in color with dark scales on their wings that form four darker spots. Quadrimaculatus is the main source for the transmission of malaria in the US. 

A major effort seemed to eliminate malaria in the U.S. in the 1950s, but it has come back, with quadrimaculatus found to be still susceptible to infection with the parasite that causes malaria. Scientists have found quadrimaculatus with infections of the salivary glands that can then be transmitted.

  • Anopheles freeborni, known as the western malaria mosquito. Adults are dark (brown to black), with yellowish hairs and stripes on the thorax. Their wings are scaly and have four dark spots. They gather in swarms that average 6 feet in height. Females can survive winter, releasing their eggs as spring arrives.

There are 460 species of Anopheles mosquitoes, of which 100 can transmit malaria. 

  • When does it bite: Between dusk and dawn, indoors and outdoors. Can be found in dark, sheltered places during the daytime.
  • What diseases does it pass on: Malaria. Anopheles not only transmits malaria in areas where it is common, but also in areas where it was eliminated. Malaria is the cause of death for 400,000 people per year. In the US, 2,000 cases turn up every year (most often from returning travelers), and there have been 60 limited outbreaks since the 1960s
  • What is its need for blood: The female Anopheles requires a blood meal to produce her eggs. When she bites an infected person, the parasite makes its way to the mosquito’s salivary glands. When the mosquito feeds on another human, the infected saliva is passed on.
  • Does it go after humans: Prefers humans and mammals to feed on
  • Where does it lay its eggs: On the water’s surface of a pond or marsh, creating a raft, or on moist soil nearby.
  • Where does it live: Marshes (freshwater and saltwater), swamps, ditches, near streams and rivers, and even in temporary pools of water that follow rains.
  • Sun or shade for the laying of eggs: In open water in the shade
  • Life cycle of the Anopheles1½ to 2 weeks
  • How far does it spread:  They don’t fly more than 1.2 miles from their habitats.
  • How to fight back: Eliminate places they breed, use netting and screens, apply bug repellent, wear long clothing. If infected, there is medication.

Culex Species

image of a culex mosquito
Culex mosquito
Photo Credit: doug4537 / Canva Pro / License

Culex has emerged as the most common mosquito found in urban areas in the U.S., especially as urban sprawl has moved into areas that were once made up of swamps and marshes.

The emergence of Culex mosquitoes in urban areas coincides with an increase in the spread of the disease they bring, West Nile virus. 

  • Culex pipiens, known as the northern house mosquito, has a small, light brown body with a dark proboscis. Its wings have narrow, dark scales. It is a major spreader of pathogens to wildlife, livestock, and humans.
  • Culex quinquefasciatus, known as the southern house mosquito, has a brown body with black and broad bands on its abdomen. It can pass on all of the diseases of Culex, and is considered the principal agent for the transmission of St. Louis encephalitis, an infection for which there is no proven treatment.
  • Culex tarsalis, known as the Western Encephalitis Mosquito, can be identified by the black and white bands on its legs and carries all the diseases of Culex. It readily enters buildings looking for blood. In the western U.S., it is a major carrier of mosquito-borne diseases, especially West Nile virus and Western equine and St. Louis encephalitis.
  • Culex nigripalpus is called the Florida SLE (St. Louis encephalitis) mosquito. Dark in color, medium in size, it has few distinguishing marks, making it difficult to identify. Culex nigripalpus breeds in freshwater and feeds on birds and humans, transmitting diseases back and forth. It lives in the coastal Southeastern U.S. but spreads northward during warm weather.

There are 768 species of Culex.

  • When does it bite: Typically at night, both indoors and outdoors
  • What diseases does it pass on: West Nile virus, encephalitis. In China, Cat Que Virus. 
  • What is its need for blood: Culex quinquefasciatus are unusual in that the males feed on blood along with the female. The female needs blood to produce eggs, but will wait several days after feeding before laying the eggs. 
  • Does it go after humans: Prefer to feed on other animals, but if there aren’t enough, will turn to humans
  • Where does it lay its eggs: On water, forming rafts of 100-300 eggs that float on the surface
  • Where does it live: In stagnant, polluted water. Prefer places that have organic matter, such as swamps, marshes, and pastures.
  • Sun or shade for the laying of eggs: In open water in sun or shade
  • Life cycle of the Culex: 1½ to 2 weeks except in cool weather, when it lives longer.
  • How far does it spread: Two miles.
  • How to fight back: Eliminate places they breed, netting and screens, bug repellent, long clothing. 

The Dangers of Mosquitoes 

Mosquitoes are important because they need human blood in order to propagate: The female sucks it into her body, but in doing so can infect the human. Humans can die from the infection.

  • Over 1 million people die every year as a result of mosquito bites.
  • More people have died from mosquito bites than from weapons.

Mosquitoes are True Flies

graphic showing a mosquito life cycle

Mosquitoes are classified in the order Diptera (true flies) and in the family Culicidae. Adult mosquitoes have these characteristics in common with other true flies:

  • Small, usually less than a quarter-inch.
  • Long-legged, but legs that can be shed when in danger 
  • One pair of wings that are narrow.

Adult mosquitoes have these characteristics that are different than all other flies:

  • Long antennae made up of 13 segments
  • A mouthpart system that allows both piercing and sucking. Mosquitoes use their distinctive mouth to inject saliva that contains chemicals that reduce blood clotting so they can use the blood. The saliva also infects the human. 
  • A distinctive beak or proboscis. It is made up of six thin, needlelike parts that penetrate the skin.
  • Wings with scales

FAQs

Which Insects are Commonly Mistaken for Mosquitoes?

Crane flies (Tipulidae), sometimes called “daddy-long-legs,” emerge from water and are attracted to porch lights, but they are not predacious.
Mayflies (Ephemeroptera) don’t look like mosquitoes, but they also come from water and are attracted to lights.
Midges (Chironomidae) fly in swarms and will be seen resting in walls and fences. They will swarm over a light-colored object, such as a car or a piece of lawn furniture.
Dixid midges (Dixidae) are found in slow-moving water, swimming in a U-shape. 
Fungus gnats (Sciaridae) are small black flies found in decaying vegetation. They can become a nuisance when plants that contain them are brought indoors.
Dance flies (Empididae) swarm in sunlit areas in backyards, leading people to think they are mosquitoes. 
Wood gnats (Anisopodidae) are attracted to light and can be found near windows, especially during the spring.

What Are the Diseases Carried by Mosquitoes?

● Chikungunya virus
● Dengue fever
● Encephalitis (several types)
● Malaria
● West Nile Virus
● Yellow fever
● Zika

Are There Predators That Help Fight Mosquitoes?

Yes, there are mosquito predators that help fight mosquito populations. Mosquitoes go to standing water to lay their eggs, but when that standing water is part of a pond or lake, there will be fish and dragonfly nymphs that will feed on the mosquito larvae. Mosquitofish, in particular, help to eat mosquito larvae before they become biting adults.

In Addition to Open Water, Where do Mosquitoes Lay Eggs? 

In objects that can be discarded or recycled:

Tires that aren’t on a vehicle
Toys unused and no longer played with
Bottle caps left about

Places that can be filled with sand:

Tree holes, even though they can be difficult to reach
Saucers that potted plants sit in 

Places that can be cleaned out:

Buckets (or turned over so water doesn’t gather)
Roof gutters, perhaps as part of regular maintenance

A Call to Action

Mosquitoes may be little more than a nuisance, but there are some that transmit diseases that can be deadly. If you see, or feel, mosquitoes, take action. Decide what you want to do, then act.

You can take on mosquitoes as a do-it-yourself project, making it a point to clean up the places where they congregate, or leave this job to the pros. To find a mosquito service near you, contact Pest Gnome to connect you with a professional. 

Photo Credit: mrfiza / Canva Pro / License

Ted Rodgers

Ted Rodgers has been an editor and writer for a half century at least, and has had to deal with pests throughout. His home is still standing, which is one (small) definition of success in dealing with them. He is willing to pause in his battles long enough to share what he has learned. He borrows from Beatrix Potter when he shares this truth about pests: “Tiddly, widdly, but not piddly.”