Both the average temperature and the number of days that people are at danger of getting bitten by a mosquito have increased in the United States.
Impacts of Climate Change: Extended Mosquito Seasons Pose Health Risks in Cleveland
A new report from Climate Central, a group that was established in 2008 to truthfully disseminate information on the consequences of climate change, supports this assertion.
For much of the nation over a number of years, the study revealed substantial increases in “mosquito days,” which are defined by Climate Central as those with average relative humidity of 42% or higher and an average daily temperature range between 50 and 95 degrees.
The report’s implications for Cleveland include that there is now a longer window of time during which residents are susceptible to West Nile virus, the main infection spread by local mosquitoes.
According to Peter Girard, a representative for Climate Central, mosquitoes prefer warm, humid air, and as greenhouse gases build and trap heat in the Earth’s atmosphere, the number of mosquito days has increased. Warmer weather has been the primary cause of an increase of mosquito days in the eastern United States, he added, while humidity levels have also increased.
As a result of the weather patterns, spring has arrived sooner and fall has lasted longer, according to Shannon LaDeau, senior scientist at the Cary Institute of Ecosystem Studies.
Regional Trends and Variations in Annual Mosquito Days
In 173 of the 242 areas in the contiguous United States, the average number of annual mosquito days rose by 16 days, according to Climate Central’s analysis of meteorological data from 1979 to 2022. The South, where temperatures frequently climb to unsuitable levels for mosquitoes, accounted for the majority of the 61 locations where the number of mosquito days actually decreased.
Cleveland had a 27 percent rise in yearly mosquito days, although it fell short of the top ten highest gainers. California has two locations where mosquito days have increased the most. San Francisco had forty-two days and Santa Maria forty-three days.
Third on the list with 33 days is State College, Pennsylvania; it is followed by Seattle-Tacoma, Washington, at 32, and Manchester, New Hampshire, at 31.
The towns of Wheeling and Clarksburg-Weston in West Virginia have 28 extra mosquito days apiece.
With 218 mosquito days annually, the Southeast leads the other regions with 184, the South with 116, the Ohio Valley with 146, the West with 132, the Northeast with 129, and the Upper Midwest with 112.
Most of the 55 sites that had a yearly rise in mosquito days of at least 21 are in the Northeast or the Ohio Valley region, which includes Cleveland.
Multiple variables influence mosquito populations, according to LaDeau. Larger numbers would be expected biologically from more days of warmer weather, but measuring that “unless you had pretty constant observation,” the speaker added, would be quite challenging.
Mosquito Behavior and Disease Transmission
According to board of health spokesperson Kevin Brennan, the Cuyahoga County Board of Health sets traps across the county to gather mosquitoes in order to look for signs of West Nile. However, the number of mosquitoes collected is not tallied.
Neither Ohio’s top 10 mosquito hotspots nor its top 10 least mosquito-prone states are listed in a report by the insurance consumer education website insuranks.com. The average temperature and precipitation, mosquito species, West Nile cases in 2022, and Google searches are used to determine the rankings.
Cleveland is neither in the bottom nor top 10 cities where mosquitoes are the biggest worry, according to insuranks.com, which compiles this data from Google queries “related to mosquito avoidance.”
In addition to temperature and humidity, rainfall volume is another component that promotes mosquito proliferation. According to LaDeau, persistent, pooling water after a heavy downpour might provide an ideal environment for mosquito growth where mosquito repeller is most needed.
According to LaDeau, mosquito numbers shouldn’t be significantly impacted by a mild drought. The population can decline due to a prolonged drought, but it can swiftly increase when it starts to rain again.
According to Climate Central, there are more than 200 kinds of mosquitoes in the contiguous United States, however the majority are not harmful. According to LaDeau, there are two species in the Cleveland region that are most prone to bite humans. West Nile virus may spread, but only if a person bites a human after first eating on an infected bird. Because it requires blood to develop its eggs, only the female mosquito bites.
According to LaDeau, tiger mosquitoes are also present in the Cleveland region. She stated that although the pests have the potential to spread the dengue, zika, and chikungunya viruses, Cleveland has not experienced any cases of these. This is because the spread of these infections is contingent upon the presence of sick individuals in the surrounding region. Before the tiger mosquito may spread the virus to another human, it must first bite an infected person.
In this regard, Biogen is planning to create an action plan to deal with these viruses spread by the mosquitoes.
Southern Florida is home to the yellow fever mosquito, which is mostly found in South and Central America and can spread dengue. Additionally, the salt marsh mosquito, which is more known for bothering visitors than for carrying disease, may be encountered at an East Coast beach.
In urban and backyard environments, open containers, birdbaths, and tires can serve as breeding grounds for mosquitoes. Because there are fewer people than animals to bite, hatchlings in natural wetland ecosystems are less likely to spread diseases.
A mosquito egg can take three days to a week to mature into an adult, according to LaDeau. After that, it will likely spend an additional week in the wild, but they can survive up to two weeks in a lab. In order to survive, a mosquito must expend more energy in order to feed itself.
According to Ladeau, in the Southeast of the United States, where there are more mosquito days and where populations survive the winter and continue to grow, humans are more likely to come into contact with a mosquito, all other things being equal.
According to LaDeau, there are certain locations where the heat may grow to the point that mosquitoes cannot survive. However, nobody will feel at ease under those circumstances either.
