Please Read: This site contains information about using pesticides. Pesticides can be dangerous if used improperly or carelessly. Always follow label instructions. The pesticide product label is the final word on the safe and legal use of pesticides. Questions about pesticide toxicity can be explored at the National Pesticide Information Center (NPIC). Control suggestions are intended for users in the state of Oregon, USA. Others should consult with local experts before relying solely on this information.

The adult crane fly is found in the late summer and early fall. It has long legs and looks very much like a large mosquito (body alone is about 1" long). One common name for these insects is "mosquito-hawk". The adults are harmless. They do not bite nor do they attack mosquitos. They are very common at night around lights.

Larvae, sometimes called "leather jackets," live in the soil. Larvae hatch from eggs laid in the late summer. They feed during the fall and into the spring of the following year. They stop feeding in May. Damage generally starts to be noticeable during the spring, caused by feeding that occurred the previous fall and winter. Damage can also occur when birds scratch at the lawn surface attracted to larvae. Birds are important predators of crane fly larvae and great care should be taken not to poison birds if insecticides are used.

European crane fly are relatively new to western Oregon. In the past we've not had many important turf pests, only occasional insect problems. Now that European crane fly has arrived, it is likely to be a permanent inhabitant of our lawns. Severely damaged lawns may need renovation. It is probably not necessary to treat these lawns with insecticides prior to renovation as normal site preparation (tilling and rotovation) controls larvae.

For less severely damaged lawns, treatment should consist of fall (October - November) applications to control larvae before damage is done or spring applications to prevent further damage. If you wish to scout your lawn in the spring, dig a patch about 12" square and about 2 inches deep. Count the number of larvae in this patch. More than 25 larvae is a sign of trouble. The European crane fly might be confused with other, less damaging, species. Specific identity is difficult. However, the presence of large crane fly adults in late summer coupled with damaged turf are good indicators of this pest.

Consult a current edition of the PNW Insect Control Handbook, available at your county Extension office, for control suggestions. Homeowners can purchase effective materials from lawn and garden stores.

National Pesticide Information Center

Iowa State University Entomology Internet Resources

OSU Extension Service

OSU Extension & Experiment Station Communications (Publications)