Discover the Top 10 Most Mosquito-Infested US States

macro normal female mosquito isolated on green leaf
© jiade/

Written by Nixza Gonzalez

Updated: July 12, 2023

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The Top 10 Most Mosquito-Infested US States infographic
Here are The Top 10 Most Mosquito-Infested US States

Mosquitos are annoying insects that can spread diseases. These biting and blood-sucking insects can also cause red bumps and skin irritation. There are some places with more mosquitos than others, including southern states. But where can you find the most mosquitos? How can you avoid being bitten? Follow along to discover the top 10 mosquito-infested US states.

1. Florida

The state with the most mosquitos is Florida. This beloved peninsula is warm and humid almost all year round, which is the perfect habitat for mosquitos. In Florida alone, there are at least 80 mosquito species, however, there are five you should know. According to the Florida Department of Health, the worst mosquitos in the state are the yellow fever mosquito, the Asian tiger mosquito, the southern house mosquito, the black salt marsh mosquito, and the gallinipper. 

 Some of these carry diseases, like the southern house mosquito, which carries the St. Louis encephalitis virus, and the West Nile virus. This mosquito is found in all Florida counties and is common near water. The number of marshes and water is likely why Florida is so mosquito-infested. To prevent mosquitos in your yard or home, always pour water out of containers. Mosquitos thrive in standing water. 

Southern house mosquitos spread diseases like the West Nile virus.

© Ray

2. Texas

The next mosquito-infested US state on our list is Texas. Like Florida, Texas has a lot of standing water and marshes, which are mosquito habitats. Mosquitos are a lot worse during the summer when the weather is warmer and humidity increases. There are over 80 species of mosquitos living in Texas, but the four most common are yellow fever mosquitos, Asian tiger mosquitos, house mosquitos, and southern mosquitos.

Mosquitos are difficult to control in Texas. There is too much flooding, which attracts breeding mosquitos. Female mosquitos lay between 100 to 200 eggs. Mosquitos need as little as a teaspoon of water to breed. Some mosquitos in Texas can transmit diseases like chikungunya, dengue, and malaria.

Tiger aka Forest mosquito macro. Aedes albopictus. Stegomyia albopicta. Vector for Chikungunya, Dengue and Yellow fever. Once primarily Asian - now spread.

Asian tiger mosquitos live in Texas, one of the most mosquito-infested US states.


3. Louisiana

Another southern mosquito-infested US state is Louisiana. This state is known for its swamps, like Florida, which are breeding grounds for mosquitos. While there aren’t as many mosquito species in Louisiana, you can still find 68! The most common mosquitos in Louisiana are the Asian tiger mosquito, southern house mosquito, woodland mosquito, dark rice field mosquito, malaria mosquito, and floodwater mosquito.

Dark rice field mosquitos are aggressive. The females are fierce biters, attacking during the day and at night. These are more common after a hurricane in flooded conditions. They carry the West Nile Virus and the Venezuelan Equine Encephalitis. After heavy rain and in the summer, it’s more common to see the inland floodwater mosquito. Their bites are painful and they are difficult to get rid of or prevent.

Dark Rice Field Mosquito

The dark rice field mosquito carries the West Nile Virus and delivers a powerful and painful bite.

©xpda / CC BY-SA 4.0 – Original / License

4. Georgia

Next is Georgia, with about 63 known species. Thankfully, out of these 63 mosquito species, only about 10 to 12 are pests that spread diseases. The most commonly reported mosquito-spread disease in Georgia is the West Nile Virus. However, you can contract other diseases like La Crosse encephalitis and Saint Louis encephalitis virus. The best way to avoid getting sick is to prevent mosquito bites. This isn’t always possible, but there are a few things you can do.

Mosquitos are most active during sunrise and sunset in early spring through fall. Wear clothes that cover your arms and legs. You can also use a mosquito repellant, but some species are resilient.

Asian woman scratching her arm skin, health care concept image of mosquito bite, allergic dermis inflammation, fungus infection, dermatology disease, malaria, dengue, tropical mosquito virus infection

To prevent mosquito bites, wear clothes that cover your skin.


5. North Carolina

North Carolina mosquitos are a nuisance. The mosquitos are mainly small and hard to notice, but deliver a painful and itchy bite that swells up. The most common mosquito-transmitted diseases in North Carolina are the West Nile Virus, eastern equine encephalitis (EEE), and La Crosse encephalitis (LAC).

North Carolina mosquitos are most active from March through October. They disappear as the weather cools down. The most common species in North Carolina is the northern house mosquito. As their name suggests, they live indoors and in yards. They are very active at night and are found in pools, birdbaths, and trash cans. However, on the eastern side of North Carolina, you can find the eastern salt marsh mosquito, which breeds in marshes along the coast.

Macro shot of Northern house mosquito (Culex pipiens) sitting on human skin

Northern house mosquitos are the most common species in North Carolina.


6. Alabama

Alabama is a southern state near Georgia, North Carolina, and Florida, the states with the most mosquitos. That’s why it’s no surprise that Alabama makes our list of the top 10 mosquito-infested US states. In Alabama, there are about 60 different types of mosquitos, however, not all are dangerous or spread diseases. The mosquitos you should watch out for in Alabama include the yellow fever mosquito, Japanese encephalitis mosquito, Asian tiger mosquito, southern house mosquito, and eastern tree-hole mosquito.

Mosquitos don’t just spread diseases to humans. Some also carry heartworm which affects dogs. Although you can prevent mosquito bites using EPA-registered mosquito repellants, it doesn’t always work. You can also use natural mosquito repellants but always reapply. One of the best ways to prevent mosquitos in your yard is to dump out excess or standing water. Don’t overwater your plants either as moisture can attract mosquitos.

A closeup shot of a Yellow fever mosquito on a green stem

Yellow fever mosquitos are common in Alabama.

©Wirestock Creators/

7. South Dakota

While most mosquito-infested US states are in the south, there are exceptions like South Dakota. In South Dakota, you can find over 40 mosquito species. However, two species are more common, the inland floodwater mosquito and the western encephalitis mosquito. Both can spread diseases like the Western Nile Virus, however, the western encephalitis mosquito is more dangerous.

You can’t always avoid being bitten by a mosquito. However, if possible, avoid going outside in short sleeves during sunrise and sunset. Always cover your pool and mow your lawn as adult mosquitos live in tall grass.

Palisades State Park South Dakota

Mosquitos are found throughout South Dakota.

©Krumpelman Photography/

8. Oklahoma

Oklahoma is next on our list, which isn’t surprising since it’s above Texas. In Oklahoma, there are at least 60 mosquito species, but the most troublesome are the yellow fever mosquito, inland floodwater mosquito, Asian tiger mosquito, common malaria mosquito, and common house mosquito.

The common malaria mosquitos are slender and long. These are common along lakes and ponds. They live in aquatic habitats and have four distinct dark marks on their wings. Common malaria mosquitos feed on humans and can wander inside. They transmit dog heartworm and malaria. To avoid letting mosquitos in your home, patch up any holes in your windows and doors.

Common malaria mosquitoes

Common malaria mosquitos transmit malaria and dog heartworms.

© – Original / License

9. Montana

It’s hard to escape from mosquitos in Montana. One study identified 50 distinct mosquito species by trapping 100,000 mosquitos. While there are many species, about 90% of the mosquito population in Montana are the inland floodwater mosquito and the western encephalitis mosquito. Both are powerful and aggressive biters, especially at night. In Montana, most mosquitos are out in spring and summer.

Yellowstone River Flowing Through Industrial Landscape with Rose Sunset - Glendive, Montana.

There are 50 recorded mosquito species in Montana.

©Paul W Thompson/

10. Virginia

Last but not least on our list of the most mosquito-infested US states is Virginia. Like Montana, there are at least 50 mosquito species. They live in aquatic environments and are common in residences near lakes or ponds. However, these pesky mosquitos can make their way into your home quickly, especially if water is left standing.  

While mosquitos are found throughout the state, they are more common in northern Virginia. One of the most common species is the Asian tiger mosquito. Although it’s rare to contract a disease from a mosquito bite, if you notice a red bump, always wash it with cold water and soap. Try to ignore the itchiness as scratching can cause infections.

Allergic reaction, itch, allergy, dermatiti concept. Close up of woman applying cream or ointment on swell skin after insect mosquito bites, isolated on grey studio background.

Always wash a mosquito bite with water and soap.


Summary of the 10 Most Mosquito-Infested US States

1Florida80 species
2TexasOver 80 species
3Louisiana68 species
4Georgia63 species
5North Carolina60 species
6Alabama60 species
7South DakotaOver 40 species
8Oklahoma60 species
9Montana50 species
10Virginia50 species

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About the Author

Nixza Gonzalez is a writer at A-Z Animals primarily covering topics like travel, geography, plants, and marine animals. She has over six years of experience as a content writer and holds an Associate of Arts Degree. A resident of Florida, Nixza loves spending time outdoors exploring state parks and tending to her container garden.

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