Experts say this a bumper spring for the inch-long grubs, which are the larvae of crane flies, better known as daddy long-legs.
Crane fly numbers exploded last autumn after heavy summer rain and now farmers who neglect their swards could pay the price.
Llandyrnog-based Merfyn Parry, an agronomist with County Crops, said he'd never seen such a bad year for leatherjackets.
"They're everywhere," he said. "The dry summer of 1976 brought an invasion of ladybirds, now it looks like we've got something similar with leatherjackets.
"Last week I went a field near St Asaph and I'd never seen such a bad infestion."
The grubs attack the roots of ryegrass and can cause heavy thinning of swards and their replacement by weed species such as annual meadowgrass.
Grassland ploughed for crops may need re-sowing if the problem is not addressed before initial drilling.
Mr Parry added: "If you can see damage to swards, such as patchiness, it's time to act.
"Four or five leatherjackets in a 1 sq m area of ploughed fields should sound warning bells. It's the same if there are more crows than normal on your fields - they feed on the larvae."
For information, contact Mr Parry on 07836 208446.
Merfyn Parry warns about a plague of leatherjackets (inset )
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|Publication:||Daily Post (Liverpool, England)|
|Date:||Apr 27, 2006|
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