How to Prevent & Control Crane Flies

Attack of the giant mosquitoes! Crane flies aren't mosquitoes, but that's what you might think when you see them buzzing around your property. The adults are harmless, but watch out for their larvae because they can wreak havoc on your grass.

Crane Flies: What You Need to Know

Crane flies, sometimes called mosquito hawks, are invasive lawn pests that are prevalent in the Northwest as well as the Northeast. While native species of crane flies live on decaying leaves, the European species attacks pastures and lawns. 

Larvae of European crane flies are also known as leather jackets. They hatch in the fall and live on grass blades until they go underground for the winter. In the spring, they'll come back out on the lawn. They're especially harmful to new grass.

Kill & Prevent Crane Flies and Larvae

Identify European Crane Fly Larvae in Your Lawn
Your lawn's appearance gives them away. In the fall and spring, look for patches of damaged grass. These patches may grow together and spread.
Where the infestation is heavy, you may see a brownish paste. Dig into your soil and look for brownish-grey larvae about 1 inch long. A few are not an issue, but if you see many (about 80 per square foot), you should take measures to eliminate them.

Stopping the Larvae
You want to kill European crane fly larvae when they're most active – usually in early to mid-April. Using a drop spreader or broadcast spreader, apply Ortho® BugClear™ Insect Killer for Lawns around your property. It kills by contact above and below the soil and will create a bug barrier that lasts three months. Be sure to follow all label instructions.

Let Nature Control the Adults
The adults are a feast for birds. Sparrows and robins love them and can do a lot to control future populations.