Crane Flies and Lawn Damage: What You Need to Know

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If you're a homeowner with a yard, you've probably heard of crane flies. These insects are often mistaken for large mosquitoes, but they don't bite humans or animals. However, they can cause serious damage to lawns in their larval stage.

In this article, we'll cover everything you need to know about crane flies and how to prevent lawn damage from them.

What Are Crane Flies?

Crane flies are insects that belong to the Tipulidae family. They're often confused with mosquitoes due to their slender bodies and long legs. However, crane flies are completely harmless to humans and animals.

In North America, there are over 4,000 species of crane flies. These insects can be found in practically every habitat, ranging from tundras to forests and even deserts.

Why Are Crane Fly Larvae Considered Pests?

Although adult crane flies don't cause any damage, their larvae can be detrimental to your lawn. Crane fly larvae, also referred to as leatherjackets, feed on the roots of turfgrass. This causes wilted, brown, and dead patches to appear in your lawn. In severe infestations, the damaged area may resemble a patchwork quilt.

The Importance of Preventing Lawn Damage from Crane Flies

Preventing lawn damage from crane flies is essential for maintaining a healthy and beautiful lawn. Infestations can occur quickly and take several years to recover from, leaving unsightly patches in the meantime. By taking the necessary preventative measures, you can save yourself time, money, and effort in trying to restore your lawn.

Identifying Crane Flies

To take appropriate measures to prevent and control crane fly damage, you need to be able to identify them. Here's what you need to know:

Appearance

Crane flies are thin insects with long legs that can span up to six inches. They range in color from brown to black and have slender bodies with large wings. Some species of crane flies may be brightly-colored, such as green or orange, and have intricate wing patterns.

Behavior and Reproduction

Adult crane flies live only a few days to a week and are often found around lights and window sills. After mating, the female crane fly lays her eggs in damp soil. The eggs hatch into larvae, which then begin feeding on turfgrass roots.

Crane Fly Larvae: Lawn Pests to Watch Out For

Identifying Crane Fly Larvae

Crane fly larvae, also known as leatherjackets, are gray or brown in color and have a worm-like appearance. They have no legs but do have visible black mandibles, which they use to feed on roots. Leatherjackets can grow as long as an inch, and there may be hundreds of them in just one square yard of lawn.

How Crane Fly Larvae Hurt Your Lawn

As mentioned earlier, crane fly larvae feed on the roots of turfgrass, causing the grass to weaken and die off. This results in patches of dead or dying grass that can become a breeding ground for weeds. You'll notice thinning and discolored grass blades, loose turf, and signs of wilting when your lawn is infested with leatherjackets.

When to Treat for Crane Fly Larvae

Take proactive measures to prevent crane fly larvae infestations before they occur. If you suspect that your lawn has already been invaded, the best time to treat for them will depend on where you live and what stage of development they're in. In most cases, August or early September is ideal for treating larvae in the Pacific Northwest. However, the timing may vary depending on your location and weather conditions.

Preventing Lawn Damage from Crane Flies

There are several preventative measures you can take to avoid crane fly damage to your lawn. Here are three ways to protect your turf:

Cultural Practices to Help Protect Your Lawn

Caring for your lawn correctly is one of the most effective ways to prevent crane fly infestations. Regular fertilization, aeration, irrigation, and mowing help to promote healthy growth of turfgrass which can resist pests and diseases. Avoid overusing pesticides or harsh fertilizers, as these can make turf weaker and susceptible to damage.

Chemical Control Options for Crane Flies

If leatherjackets have already damaged your lawn, there are several chemical options for controlling them. Chemical control methods vary depending on your preference and the severity of the infestation. You may choose chemical sprays or granules, which can be applied via watering cans or spreaders.

How to Monitor Your Lawn for Signs of Damage

Routine pest monitoring is an essential component of good lawn care. In early spring and late autumn, assess your lawn visually or use a trowel to carefully dig up sections of sod. Look for signs of leatherjacket activity, such as withering and browning of grass blades or visible larvae feeding. You may also use pheromone traps to capture adult crane flies and determine if they're present in the area.

Don't let crane flies damage your lawn: be proactive about prevention

By implementing some preventative measures, you can guarantee a healthy and thriving lawn. Regular yard care practices like proper watering, fertilizing, aerating, and mowing will maintain strong turfgrass that resists pests and diseases. Additional pest prevention methods, including chemical control and routine monitoring, can stop an infestation before it starts.

Keep an eye on your lawn year-round to avoid costly repairs and replacements.

Regular lawn care is the key to maintaining an attractive, weed-free lawn. Depending on where you live, fall or early spring is the best time to consider fertilizing, but you can also do this in midsummer. Avoid going too long without routine lawn care and maintenance, as this may leave your lawn susceptible to pests like crane flies.