25th Mar 2021
Leatherjackets are the larvae of crane flies (daddy-long legs), which are a common nuisance in some lawns. These pests are 30-40mm long and can cause significant damage when left untreated.
Crane flies are on the wing between late July and early September. During this time they lay their eggs below the surface of the turf. The larvae or (leatherjackets) then hatch 2-3 weeks later. They then start devouring the turf roots and stem bases with biting mouthparts. The larvae can then feed right through to the following June.
One of the main problems with Leatherjackets is that it can take a while to even notice they are present, at which point quite a lot of damage has already been caused. The damage caused by leatherjackets does not become obvious until the spring when they are growing rapidly. The first visible signs of damage can be seen when straw-coloured patches of turf appear, which later become bare and usually become infested with weeds.
An Increase in Wildlife Activity Can Be a Sign of Leatherjackets
Leatherjackets in your lawn can become clear if magpies, crows or flocks of starlings descend on the lawn. Leatherjackets are also a favourite of hedgehogs, foxes and badgers. If visiting wildlife has been taking more interest in your lawn than usual, it could be a sign of unwanted activity beneath the surface.
Leatherjackets damage lawns by the feeding on the root of the grass plant causing dead patches, but often more significant damage is caused by wildlife searching for them.
Like anything, prevention is always better than cure. When identified early, leatherjackets can easily be controlled with a single application. However, a lawn with significant leatherjacket damage may require renovation work.
In order to help avoid the damage that these pests cause, areas of the turf should be checked on a regular basis to see if any larvae are present. One method of identifying leatherjackets is to try and peel back areas of your lawn. If the turf easily rips up like a mat, then you may have leatherjackets which have already fed on some of the roots.