CRANE FLY LARVAE IN LAWNS
CRANE FLY, Tipula sp., Tipulidae,
Adult crane flies, Tipula sp., resemble giant mosquitos. The wing span may be two inches across. Adults are clumsy and weak fliers. They are often found resting on an outside wall of a house, under a porch or in a garage. They may gain entry to a house when a door or window is opened. However, crane flies are harmless to humans. They cannot bite and have never been implicated with any disease. Adults are short lived and may feed on floral nectar or not at all. There are many species. Some new invasive species (Tipula oleracea L. and T. paludosa Meigen) are beginning to cause damage or problems in turf in New York.
The larvae (maggots) of crane flies are sometimes called leatherjackets because of their tough skin. They are commonly two to three inches long and have no legs. Leatherjackets sometimes infest tobacco plant beds where they apparently feed on the roots of the tobacco seedlings and are of some economic concern. Some species are reported occasional pests of turf or pasture and forestry seedling beds, mostly in the North Western United States. Some species of crane flies have predaceous maggots (feeding on other invertebrates) and some feed on decaying organic matter. They may be more noticeable above ground at night. Some species have aquatic larvae. Around homes, larvae may be developing in wet turf, nearby streams or in the surrounding damp woodlands. Adults are very short-lived, but there could be extended adult emergence periods during a season making it appear that the adults live more than a few days. Populations decline when soils dry.
Control measures are rarely required in NC and could introduce chemicals unnecessarily to the environment and waste money. To monitor populations in turf, cut three sides of a 6" x 6" square of turf with a knife. Pull back the flap and examine the root zone. Soapy water flushes may be a good diagnostic tool for determining maggot populations. If the sample of the turf reaches 25 larvae, they may be numerous enough to do damage to weak turf. Healthy turf may sustain 40 or more larvae per sample. Suggestions include keeping turf strong and healthy without overfertilization. Try to eliminate situations where lawns stay overly wet for long periods by improving drainage. Temporary relief might be achieved by raking larvae up at night and drowning them in a bucket of soapy water or take the day off and use them to go fishing. Application of turf insecticides often cause cause maggots to come to surface to die. Acelepryn is one such product labeled for European crane fly larvae with application in fall.
Fishermen may enjoy tying flies of the adults, though I suspect the larvae to be better bait.
Photo Credit- Adult, Drees, Texas AMU. Larva, unknown
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Prepared by: S. Bambara, Extension Entomologist
Distributed in furtherance of the Acts of Congress of May 8 and June 30, 1914. Employment and program opportunities are offered to all people regardless of race, color, national origin, sex, age, or disability. North Carolina State University at Raleigh, North Carolina A&T State University, U.S. Department of Agriculture, and local governments cooperating.
ENT/ort-129 April, 2003
Web page last reviewed January, 2011 by the webperson.