Crane Fly Larvae in Turf
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.
Control measures are rarely required in North Carolina 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.
Control measures are rarely required in North Carolina and could introduce chemicals unnecessarily to the environment and waste money. 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.
This Extension factsheet can also be viewed at: