Vine weevil
Vine weevil adults nibble neat notches from leaf edges at night; their white C-shaped grubs do the real harm, eating roots through autumn and winter. Container plants, strawberries and blueberries suffer most.
Pests
What it looks like
Notches above, grubs below.
-
Notched leaves Irregular notches along leaf margins. -
Sudden collapse Plants wilt and come away without roots. -
White grubs Cream C-shaped grubs with brown heads in the compost. -
Night beetles Dull black beetles with pale flecks.
How to confirm it
Tip out the pot.
-
Look for grubs
C-shaped grubs among the roots.
-
Night patrol
Adults feed after dark on leaves.
-
Container plants
Pots are far more at risk than open ground.
What to do
Nematodes are the key.
-
Apply nematodes
Water Steinernema kraussei nematodes into pots in late summer and spring.
-
Remove grubs
Shake compost off rootballs and pick out grubs.
-
Hunt adults
Collect beetles by torchlight.
-
Repot
Repot survivors in fresh compost.
Prevent it next time
- Check the rootballs of bought plants.
- Treat pots with nematodes each autumn.
- Use barrier glue on pot rims.
What not to do
Do not ignore notched leaves in summer; they mean grubs in the pots by autumn.
In the growing guides
Where the guides mention it, with plant-specific advice.
Sources
- Vine weevil, Royal Horticultural Society