PestRoot problem
Leatherjackets
Grey-brown, legless larvae of crane flies that eat grass roots, causing yellow patches in lawns, especially in the UK.
Also known as: Crane fly larvae, Daddy-long-legs larvae
Symptoms and identification
Yellow or brown patches in lawns in spring, and birds pecking at the turf. Lifting the turf reveals tough-skinned grey grubs.
Causes
Crane flies lay eggs in lawns in late summer, and the larvae feed through fall, winter and spring. Wet autumns increase numbers.
Organic treatment
Apply beneficial nematodes (Steinernema feltiae) to moist soil in early fall. Cover a wet patch with plastic overnight to draw grubs to the surface for removal.
Prevention
Keep lawns healthy with good drainage and feeding.
Chemical treatment (use with care)
Few products are available for home use; nematodes are the main control.