Privet leaf miner damage

Following the winter’s damage, I’ve been keeping an eye out to make sure the privet bushes recover OK. By and large, they are doing just that. However, I’d say some are a little weaker than would be usual, but it’s hard to tell. One thing I have noticed though is a surge in the amount of leaf miner damage.

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Damage on a privet leaf caused by leaf mining caterpillars (Gracillaria syringella)

The damage first shows as brownish marks on the leaves. They quickly expand to become a large brown blister. By this stage the blisters are easy to pull open and inside there are little tribes of larvae living a sheltered life between the upper and lower leaf surfaces.

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Inside the blister there are little tiny caterpillars – they’re quite hard to see and to photograph because as soon as their blister is burst they try and wriggle away to hide

These larvae will grow up to become tiny little micro moths – Gracillaria syringella. As the name suggests, they also mine lilac (Syringa) leaves and are known as lilac leaf miners as well as privet leaf miners. There are plenty of them on the lilac bushes this year too.

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Leaf miner damage on a lilac leaf
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…and here are the larvae inside the lilac leaf’s blister

 

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Cork oaks: assessing winter’s damage

Winter has been long and fickle this year. Mainly, I’d say, it’s been drier and colder than usual, with fewer storms. But between the cold periods there have been unseasonably warm spells (up to 20C); between the dry spells there have been huge rain storms; and between the calm spells there have been some ferocious and freezing winds. Tipyn o bopeth (a bit of everything) really and quite challenging in the garden.

The young cork oaks (which are now two and three years old) have mainly suffered from the tortrix moth caterpillars, as per usual.

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Tortrix moth caterpillar damage on cork oak

But in addition, they have also been being eaten by some kind of leaf miner…

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Leaf miner and freeze damage on cork oak

and the younger trees have suffered a little from the lack of moisture and freezing winds – showing in the orangey-bronzey tints you can see  in the picture above, alongside the dull buff colour where the leaf miners have stripped the living cells.

However, I’m happy to say, that they all seem to have come through OK and have plenty of new buds for this year’s growth. Hopefully winter will soon go away and they can put on some strong new growth through the summer.

Leaf miner damage on lovage

The leaves of these lovage plants are being damaged by the larvae of the celery fly (Euleia heraclei).

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Leaf miner damage on lovage leaves

The celery fly itself is tiny and mainly goes unnoticed, but once the female has laid her eggs into the leaves of your celery, or lovage, or parsnips, or parsley (or quite a few other plants), you’ll certainly notice the damage they do.

The egg is inserted under the skin of the leaf and the grub lives between the two leaf faces, chomping away and destroying the leaf from the inside. This causes the characteristic scorched appearance and blistering.

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The damage is, aptly, called a blotch mine (you can almost make out the grub in this blister)

The grubs will spend two to three weeks inside the leaf, growing bigger and bigger. They will then either pupate within the leaf, or in the ground underneath the plant. A new generation of flies will emerge a few weeks later ready to start the second cycle of infestation.

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One leaf, two lesions – these are still quite fresh and there will be active grubs inside
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…and here’s the grub

The only thing you can really do, on a garden scale, if you are affected by celery flies is to pick off and destroy damaged leaves as you notice them.