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What State Has the Least Mosquitoes?

Mosquito populations across the US have grown in recent years and they are starting to become a nuisance. You may be surprised to learn that their numbers are still lower today than they were a couple of centuries ago. The swamps and meadowlands of States like Florida and New Jersey were brimming with these insects before the State governments launched The Mosquito Crusade to get rid of the problem.

So which US state has the lowest number of mosquitoes? We can’t give a definitive answer to that. However, careful analysis suggests that the number of mosquitoes is comparatively lower in states like Nevada, Hawaii, Delaware, and West Virginia. The Capital area DC is a contender for low mosquito populations.

Major factors that Affect Mosquito Population

There is no confirmed scientific study on mosquito populations around the country with the comparison of numbers on a state by state basis. It is just not feasible or economical to do this.

If you are serious about knowing the number of mosquitoes in each state, however, you can make a hypothetical judgment. There are several factors that should be considered.

Size of the State

The size of the state matters a lot. The biggest state is in size, the more area for mosquitoes to spread and grow. Delaware and Rhode Island, being the two smallest states, are likely candidates for the least number of mosquitoes in the country.

The problem is that both of these states are next to large bodies of water, the preferred breeding ground for mosquitoes. They are also heavily populated with developed urban centers.

Mosquitoes are obviously going to be more visible in closely packed human communities and cities. This is why most people would dismiss Delaware and Rhode Island as the states with the least number of mosquitoes, even if it is factually correct.

Climate and Open Bodies of Water

Mosquitoes lay their eggs on open bodies of water. They also need a mild temperature and hosts to breed most effectively.

Given these factors, the states with the least population of mosquitoes are going to be hot, arid states like New Mexico and Arizona. These states are relatively dry with extremely hot temperatures that are likely to kill mosquitoes by drying out their body temperature. However, these states also have large cities and communities which report that mosquito problems are just as bad here as anywhere else.

Nevada, on the other hand, is a different case and the most likely candidate for the least mosquitoes in the country. More than 60% of the state area consists of hot deserts with little to no population. The only urban centers are on the southern and western borders of the state. Since there are no major bodies of water or significant wildlife in the state, it is possibly the state with the least mosquitoes in the country.

Species of Mosquitoes

One factor of mosquito populations can be measured scientifically. While you cannot count every single mosquito out there, you can get samples of a few and test them in the laboratory to identify their species. Scientists have analyzed various mosquito species in the US and the results have been quite interesting.

Researchers have reported that West Virginia has the least number of mosquito species at 26 only. Texas, on the other hand, has the most species at 86. This is not to say that West Virginia has the least mosquitoes. It is possible that a single species has spread out in much larger numbers in the state while they have adapted differently in Texas due to environmental factors.


Speaking of mosquito species, geographic isolation also limits the spread of pests and insects from one place to another. Human activity and travel, on the other hand, are the biggest cause of spreading insects, rodents, and other species of animals.

Consider the case of Hawaii. Mosquitoes were not originally found on the island state. They were introduced through here via whaling ships during the early 1800s. Frequent travel to the island for fishing activity and tourism caused a massive increase in the number of mosquitoes.

Research shows that many native species of animals found on the island have not developed resistance to the various diseases carried in mosquitoes. Scientists discovered six species of mosquito on the main Hawaii islands. At least two of them carry deadly human diseases (dengue, chikungunya, and Zika). One species carries avian malaria that affects birds and poultry.

Nonetheless, the isolation of the Island state makes it a possible candidate for the state with the least mosquitoes in the US.

Pest Control Activity Legislation

Control activity for various pests and insects can significantly affect their population. Strong chemical-based pesticides can bring the numbers down and effectively exterminate mosquitoes. However, these insecticides are often not advised as they can affect humans as well.

Take the case of DDT, which was once declared the wonder chemical that could get rid of all kinds of pests, including mosquitoes. The chemical was banned in 1972 after we discovered its health hazards to humans and other wildlife. It is still being used in some countries to control mosquitoes.

Insecticide manufacturers have now developed advanced chemicals that kill mosquitoes while having a minimal impact on other life forms. States with more relaxed insecticide laws are believed to have better control measures that help keep mosquito populations low.

Interestingly though, it is states like Florida and Texas that have the biggest mosquito populations that have the most relaxed laws on the use of insecticides against mosquitoes.

The Spread of Disease

Last but not least, the severity of mosquito-borne diseases can be used to identify and measure the mosquito populations in the country. Several mosquito species carry painful, even deadly diseases like Malaria, Dengue, and Zika Virus. We can use the data from research on these diseases to identify the states that are most and least affected by mosquito bites.

Based on the research so far, the southern states appear to be the most affected by mosquito based diseases. The US states up north along the Canadian border reported the least cases, so we can assume that mosquito activity is lower in those states.

It should be noted here that the data only represents the number of patients infected by the mosquito-borne disease. It still doesn’t give us clear indications about mosquito populations.

A lot of mosquito species, for instance, do not carry any disease, although they still feed on humans. It is possible that the disease-carrying mosquitoes haven’t spread up north.


Mosquito numbers have grown in recent years across the US. The problem is still not as bad as it was a hundred years ago. Some researchers believe that the ban on certain chemical pesticides has made the problem worse. However, it has also been revealed that mosquitoes had developed a resistance to toxic sprays and we need to continually come up with better solutions.

While we cannot say with complete certainty which state in the US has the least number of mosquitoes, we looked at some facts and shortlisted the possible states that have the least mosquitoes in the US.