The European Crane Fly, Tipula paludosa, often called
leather jacket, is a significant turf pest of the northwest United
States, ranging from Vancouver down to south of Portland Oregon. The
larvae of the crane fly live in the turf thatch and feed primarily on
grasses of lawns and pastures but have also been known to feed on
strawberries, flowers and vegetable crops. When feeding below the
surface, the larvae mainly attack root hairs, roots and crowns. At
night, the large larvae will migrate to the soil surface, disrupting
the soil surface and killing young seedlings. When above ground, they
will feed on stems, grass blades and leaves. In the spring, turf can be
severely damaged by the emerging larvae, causing small irregular brown
patches that can be misdiagnosed as disease damage. In the fall, damage
can occur from large levels of infestation of newly hatched larvae.
Adult European Crane Flies resemble overgrown mosquitos with
extremely long legs. They are 3-4 inches long and occur primarily in
damp locations where vegetation is abundant. They emerge shortly after
sunset, finish mating by dawn and lay eggs by dawn of the same night.
The adults do not feed but after mating lay their eggs in moist turf.
The eggs are shiny black and about 1/3rd inch long. The larvae are
light gray to greenish brown and have irregular spots. The insect over
winters as a larvae and feeds vigorously from April to mid May. They
remain inactive until mid-July when they pupate and emerge in late
August and September. Eggs hatch within 11 -15 days and the larvae
begin feeding until late November, overwintering primarily as third