Insect I.D.: Aug. 2001, VITAL STATISTICS: The Crane Fly Classifieds

Adult crane flies are slender-bodied, brownish-tan, long-legged, mosquito-like flies with two smoky-brown wings. They are commonly seen flying singly or in swarms around ponds, streams, meadows and golf courses at twilight. European crane fly adults emerge after sunset in southwestern British Columbia and western Washington, and can become so numerous that they cover the sides of houses overnight. On golf courses, the adults of other species become nuisances as they fly in the faces of golfers passing through swarms.

DIAGNOSIS. Larvae feed on roots and crowns below the surface and on grass blades and stems on the surface. The European crane fly causes bare and/or sparse turf areas, which become evident from March to April.

Unless extremely numerous, other species, apparently, cause little damage. Native species also feed on decaying thatch or may be associated with turf damaged during winter months by diseases.

LIFE CYCLE & HABITS. The European crane fly seems to require mild winter temperatures, cool summers and average annual rainfall of at least 24 inches. Adult flies emerge from lawns, golf courses, pastures and roadsides from late August to mid-September. Mated females begin to lay black, oval eggs within 24 hours after emerging. In about two weeks, the eggs hatch into small, brownish maggots, which begin feeding by using their rasping mouthparts on plant roots, rhizomes and foliage. By winter, the larva has molted twice and reached the third instar. These larvae feed slowly during winter temperatures and reach the fourth instar in April and May.

The leather jackets stay underground during the day but come to the surface to feed on damp, warm nights. Damage resembling that caused by black cutworms can occur on golf course greens.