European Crane Flies
- What they look like: Adults resemble large mosquitoes and appear in late summer and fall. They do not bite or sting. Larvae, called leatherjackets, are small, brown and wormlike.
- Damage: Leatherjacket larvae feed on grass roots in spring and summer, creating brown patches. Heaviest feeding occurs as leatherjackets mature in summer.
- Diagnose: Cut a three-sided 6- to 12-inch-square of sod. Dig down 4 inches. Peel the sod back and look for leatherjackets. In a healthy lawn, 25 leatherjackets per square foot of lawn will cause damage. Also watch for birds patrolling your lawn, digging for the larvae.