Watch for European crane fly injury to turfgrass in April and May

European crane fly is now established in many locations in southeast Michigan and near Grand Rapids. Here are management recommendations for heavily infested turfgrass and lawns.

European crane fly adult. Photo credit: Dave Shetlar, OSU
European crane fly adult. Photo credit: Dave Shetlar, OSU

Two species of crane flies from Europe, Tipula paludosa (European crane fly) and Tipula oleracea (common crane fly), are now established in many locations in southeast Michigan and in the greater Grand Rapids, Michigan area. The adult stage of both of these pests looks like a giant mosquito with a wing span of more than 1 inch. They prefer moist soils, so they are most likely to be found in irrigated turf, although with enough rain they can develop in almost any lawn.

The European crane fly adult flies, mates and lays eggs in August and September and may be seen in or near infested lawns or golf turf in large numbers. The second species, the common crane fly, also emerges from late July to September, but may also have a second generation of adults that emerge in the spring. The larvae of both species, called “leatherjackets,” grow to become nearly 1 inch long and look like a brown or gray caterpillar with no head or legs.

European crane fly larvae
European crane fly larvae right. Photo credit: Dave Shetlar, OSU

In October the leatherjackets consume enough turf roots, stems and leaves to cause visible injury to lawns or golf courses. Turf damage begins to appear as a general thinning of the infested turf, but may progress to large, dead patches. Symptoms like thin turf and digging activity by skunks and raccoons may appear to be caused by grubs, but the presence of gray- to tan-colored leatherjackets will confirm the pest as European crane fly.

Leatherjackets can be brought to the surface by drenching with a soapy water solution of 1 ounce dish wash soap in 2 gallons of water. Leatherjackets also tend to come to the surface when an insecticide is applied. This can be a nuisance on golf courses if large numbers of leatherjackets appear on tees, greens and fairways.

Turfgrass treated for grubs in the spring are not protected from European crane fly damage in October. However, if grub treatments are made in July or August, they should also protect against European crane fly damage in the fall. See the table below for a list of products that are effective against European crane flies. Note: Fall treatments tend to give better results than spring treatments, but the best products also provided reliable control in the spring as well. If homeowners discover damage confirmed to be caused by European crane fly in their lawn, they can contact a lawn care company or purchase and apply Sevin (carbaryl) themselves according to product label directions.  

Professional products to use for European crane fly and best timing as reported in university research tests at locations with a climate similar to southern Michigan

Time of year

Product

Percent (%) control

October (late July to October)

Safari, Arena, Allectus

85-100

October

Merit, Sevin, Talstar

50-95

Late April to mid-May

Arena, Safari, Aloft, Meridian

80-100

Late April to mid-May

Dylox, Merit

75

Late April to mid-May

Tempo, Allectus, Sevin

35-60

Michigan State University Extension is still looking for a good test site in Michigan where we can conduct an efficacy trial. This could be irrigated rough on a golf course, or a large lawn area where we can maintain control plots which may have some damage. We would appreciate any suggestions you may have for potential sites. If you know of a good location, please send an email to Terrance (Terry) Davis at tdavis@msu.edu.

Dr. Smitley’s work is funded in part by MSU’s AgBioResearch.

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