It's almost fall. When are Indiana's mosquitoes going to %#$! die already?

Date:2025-08-28 17:48:53 Category:US Views:1 Comment:0

Indiana mosquitoes are a pain in the butt — or the arm, or the leg, or even the ankle. Itchy bites from these annual pests often leave painful, red welts triggered by an alergic skin reaction.

So when can Hoosiers expect relief from mosquito season?

Besides being a nuisance, mosquitoes can spread dangerous diseases. Last year, 11 people were infected by West Nile virus in the Hoosier State, according to the Indiana Department of Health.

As of Aug. 27, at least 10 human cases of mosquito-borne illnesses have been reported in Indiana, with four in Marion County.

Here's what we know about Indiana's mosquitoes along with our favorite time of year — when these little biters finally start to die.

When is mosquito season in Indiana?

Indiana's mosquito season officially runs May 1 - October 1, according to the Harrison County Health Department, but the timing can vary slightly depending on how early and how long warm and humid weather sticks around.

This year, if Indiana's fall weather remains warm like it did in 2024, Hoosiers could be scratching away at mosquito bites for several more weeks into October.

The southern house mosquito, originated from Africa, transmits West Nile Virus from birds to humans globally and in Savannah. It can be found in cities and suburbs, and has adapated to breeding in stagnant water sources including storm drains

At what temperature do mosquitoes become inactive?

Mosquitoes are active when temperatures remain above 50F, say pest experts. They're most active when the weather is between 60-80F with moderate humidity.

Once temperatures drop and stay below 50F, mosquitoes find shelter. While adults die in cold weather, their eggs can survive freezing temperatures until the return of spring.

How long do mosquitoes live?

Male mosquitoes feed on nectar, mate and die off quickly, one expert told USA TODAY, but female mosquitoes — the ones that bite — can live upwards of four weeks when temperatures are ideal.

How long do mosquitoes live? Here's how (and where) they thrive in your yard.

First hard freeze of the year signals end of Indiana mosquito season: Here's when that happens

According to the Gibson County Health Department, Indiana's mosquito season lasts until the first hard freeze of the year, or when temperatures drop below 28F for several hours.

Records kept by the National Weather Service show Indianapolis residents can expect the average first freeze of the year (when temperatures drops below 32F) by Oct. 28. The first hard freeze hits usually around Nov. 5.

Story continues after photo gallery.

Why do mosquitoes drink blood?

There are more than 50 species of mosquitoes buzzing around Indiana, according to Purdue's Department of Entomology. They drink blood from wild birds, including cats, dogs and horses, but humans are still very much on the menu.

Female mosquitoes drink blood to help stimulate their production of eggs. Sight and smell, say experts, play an important role in who they bite.

One way to prevent mosquito bites: Avoid wearing dark colors

Researchers at the University of Georgia say people dressed in dark colors who are actively moving about, and those who exhale more carbon dioxide, make attractive targets for hungry female mosquitoes.

Dark-colored clothing is attractive to daytime-feeding mosquitoes, according to the Harrison County Health Department, because it resembles the shadows where mosquitoes like to hide.

A mosquito draws blood from a person's arm â€” a reminder of the health risks posed by rising mosquito populations and the importance of prevention.

But a mosquito will often smell you first.

The antennae on mosquitoes can detect trails of carbon dioxide — signaling there's a tasty human host nearby — from up to 120 feet, or 40 yards away, say health experts.

Stopping mosquito bites: Three things experts say 'don't work'

The Indiana Department of Health cautions Hoosiers from relying on pest control measures that might not work or are "ineffective" in reducing mosquito populations. These include the following:

Small ultrasonic electronic devices: Meant to be carried on the body, these devices are advertised to emit sounds that supposedly repel mosquitoes. Lab studies show these devices "do not work," according to the Harrison County Health Department.
Setting up bird and/or bat houses: Health officials say setting up bird and bat houses has "been unsuccessful in reducing local mosquito populations." Birds and bats eat many types of insects, not only mosquitoes.
Backyard "bug zappers": These products are advertised to lure and electrocute insects but health experts say mosquitoes are more attracted to humans than to these devices. One study, they write, showed that of all the insects killed by these devices, only 0.13% were female (biting) mosquitoes.

Want to get rid of mosquito populations faster? Do this

Mosquitoes breed in water. To reduce their numbers, eliminate the places they call home. Health officials in Indiana recommend Hoosier homeowners do the following:

Make sure roof gutters drain properly. Clean clogged gutters whenever needed.
Remove all discarded tires from your property. Used tires have become the most important domestic mosquito breeding habitat in this country.
Do not allow containers to hold water. Dispose of tin cans, plastic containers, ceramic pots, or similar water-holding containers. Do not overlook containers that have become overgrown by vegetation.
Drill holes in the bottom of recycling containers that are left outdoors. Drainage holes that are located on the sides collect enough water for mosquitoes to breed in.
Tightly screen "rain barrels" to ensure that mosquitoes cannot deposit eggs on or in the water.
Clean and chlorinate swimming pools, wading pools and outdoor hot tubs. If not in use, empty and cover them.
Drain water from pool covers.
Aerate ornamental pools or stock them with fish. Water gardens are fashionable but become major mosquito producers if allowed to stagnate.
Turn over wheelbarrows and change the water in birdbaths at least twice a week.
Eliminate any and all standing water on your property. Use landscaping as needed. Mosquitoes will develop in any puddle that lasts for more than 4 days.
Make sure doors and windows have tight-fitting screens. Repair or replace all screens in your home that have tears or holes.
Drain or turn unused boats or canoes upside-down to prevent water from gathering inside.