Ohio doesn’t really spring to mind when we think of mosquito-heavy states, but it is quietly plagued with them: two of Ohio’s three largest cities (Cleveland and Cincinnati) were included in Orkin’s Top Mosquito Cities for 2021. Ohio’s largest city, Columbus, also made the list in 2017.

There are about 60 different species of mosquitoes in Ohio, and while most deliver irritating but ultimately harmless bites, several are capable of transmitting serious, possibly even fatal diseases, such as encephalitis and malaria.

When are Mosquitoes Active in Ohio?

Mosquitoes are active in the warmest months, usually May through October. Mosquito activity will die down after the first frost in the fall. Generally speaking, mosquitoes are most active around sunrise and sunset since direct sunlight and high midday temperatures can easily dehydrate them. This is why keeping your grass relatively short helps keep mosquitoes at bay—they are unable to effectively hide from the sun’s rays.

Common Mosquito-Borne Diseases in Ohio

Mosquito-Borne diseases are always a concern, no matter where you live. Mosquito diseases that occur locally in Ohio include the following:

• Eastern equine encephalitis (EEE) virus. EEE is rare, with only a few cases reported each year in the US, but it is very serious. Approximately 30% of people with EEE die, and survivors are often afflicted with various neurological problems. EEE is maintained in a cycle between Culiseta melanura mosquitoes and birds. However, Culiseta melanura is not considered to be an important vector of EEE to humans because it feeds almost exclusively on birds. Transmission of EEE to humans requires another mosquito species to create a “bridge” between infected birds and uninfected mammals, such as humans. Most of the bridge species are within the Aedes, Coquillettidia, and Culex genera.
• La Crosse virus. This disease is most commonly spread by the eastern treehole mosquito, which become infected by taking blood meals from infected mammals, especially squirrels and chipmunks. La Crosse virus is endemic in Ohio, and Ohio has more reported cases than any other state in the US, averaging about 20 a year. Many people infected with La Crosse virus have no obvious symptoms, but those who do, symptoms usually begin 5 to 15 days after a bite and include non-specific symptoms such as fever, headache and nausea.
• St. Louis encephalitis (SLE) virus. Most people infected with SLE do not show symptoms, but for those who do, the time from infected mosquito bite to feeling sick (i.e., the incubation period) ranges from 4 to 14 days. Symptoms usually start abruptly, with fever, headache, dizziness, nausea, and general weakness. Some people might show signs of central nervous infections, including infections of the brain (encephalitis) or the matter around the brain (meningitis). Such symptoms might include a stiff neck, dizziness, confusion, and tremors. Between 5 to 20% of those with SLE die, the risk of death increasing with age.
• West Nile virus (WNV). Most people are infected in Ohio by the northern house mosquito. The mosquitoes become infected after they feed on infected birds. WNV is now firmly established in Ohio and cases occur each year. About 80% of people infected with WNV won’t show symptoms, but for those who do, symptoms usually set in 2 to 14 days after the bite. Symptoms usually include headache, fever, body aches, nausea, and vomiting. Death occurs in around 10% of patients diagnosed with severe WNV.

Common Mosquito Species in Ohio

Culex Pipiens (Northern House Mosquito)

These brown mosquitoes of medium size have cross bands of white scales on the abdominal segments, but have no other prominent markings. They commonly enter houses, and are vectors of SLE.

Aedes triseriatus (TreeHole Mosquito)

These black mosquitoes have silvery white scales at the sides of the thorax. They breed mostly in tree holes, tires and other artificial containers. Aedes triseriatus is the principal vector of LaCrosse encephalitis in Ohio.

Aedes vexans

Considered the principal pest mosquito in Ohio, this medium-sized brown mosquito has narrow rings of white scales on the hind tarsi and a “V” shaped notch at the middle of each band of white scales on the upper surface of the abdomen. This mosquito is very abundant and breeds in rain pools, flood waters, roadside puddles, and most all temporary bodies of fresh water.

Mosquito Control in Ohio

Most of the time, mosquito bites are annoying but virtually harmless. However, you’ll never know if a mosquito is carrying a disease or not. Therefore, it’s best to try and remove them from areas you frequent to the greatest extent possible. At MissQuito, our all-female team of trained experts targets mosquitos throughout their entire lifecycle using a variety of eco-friendly repellants. With same to next-day consultations, and the ability to work around your schedule, our mosquito control is as convenient as it is effective.