Leatherjackets are the soil-dwelling larvae of flies known as crane flies or daddy-longlegs.
How to tell if leatherjackets are a problem in your garden:
- Leatherjackets have elongate tubular bodies, up to 30mm long, and are greyish brown. They have no legs or obvious head
- Lawns develop patches where the grasses turns yellowish brown and often dies.
- Crows, magpies, rooks and starlings will search for leatherjackets in turf. These birds leave small round holes in the turf where they have inserted their beaks.
There several species of leatherjackets (larvae of crane flies) that feed on the roots and stem bases of lawn grasses and other plants.
The adult crane flies or daddy-longlegs mostly emerge and lay eggs in the turf or soil surface from August to October. Dry soil conditions at that time can result in many of the eggs failing to hatch.
The eggs hatch a few weeks after they have been laid and the young leatherjacket begin feeding on plant roots. In cold winters, they overwinter as small larvae and do not grow large enough to cause significant damage until mid-summer. Mild winters allow the young larvae to continue feeding and they can be large enough to cause lawn problems by late winter.