Leatherjackets

in : Problems: Lawns

Symptoms

Grass growth slows down and yellow, dying patches appear in the lawn. Dead and dying grass can be easily pulled up to reveal little or no root growth.
Find it on lawns, strawberries, brassicas, some ornamental plants
Time to act spring to autumn

Problem categories

Overview

Leatherjackets are the larvae of crane flies, or daddy-longlegs. The female fly lays up to 300 eggs in the lawn in late-summer. These hatch after a couple of weeks into grey-black, legless larvae that have a tough, leathery skin, hence the name 'leatherjacket'. From autumn through to summer, the larvae feed on the roots of plants, eventually growing to 5cm in length before pupating and emerging as adult flies in late-summer.
Solution
Grass growth slows down and yellow, dying patches appear in the lawn. Dead and dying grass can be easily pulled up to reveal little or no root growth.
Organic
After heavy rain or having thoroughly watered any yellow patches in the lawn, cover them with black plastic sacks and leave overnight. The leatherjackets will come to the surface and can be collected in the morning. Encourage natural predators, such as spiders and garden birds, especially starlings. Use the biological control Steinernema feltiae, which should be applied while the ground is still moist and warm in late-autumn.
Chemical
Treat the lawn with an insecticide containing imidacloprid from May to October.

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Talkback: Leatherjackets
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pampam 24/11/2011 at 15:28

the above has been most useful
100's of larvae have been appearing
before i read the article i have been gathering them
myself and my neighbour are infested with them
now we can deal with the problem without hopefully having to deal with a new lawn, thank you

tonybarnett 24/11/2011 at 15:28

my lawn has appearance of being dead im many places and has been like this for last 2 months. . Nowmagpies are making a complete mess and digging big holes all over lawn.What can I do to bring back grass. If it means heavy scaryfing and reseeding what soil do I use to fill in the holes and uneven ground I have previously used lawn top dressing but it is so fine and dusty Can i use an insectide

Tony barnett