Vine Weevil - How to identify and get rid of (2021)
Vine weevil (Otiorhynchus sulcataus) is a common UK garden pest affecting over 200 plants and fruits like strawberries. It’s active from Spring to Autumn. Natural nematodes applied to the soil offer the best treatment.
What plants do vine weevil like?
British weevils are common pests that feed on over 200 species of plant, including fuschia and rhododendron, as well as berry fruits, like strawberries and raspberries.
They particularly like those grown in pots or containers.
Vine weevils love potted plants
A full list includes: Arisaema, Aster, Astilbe, Azalea, Begonia, Bergenia, Camellia, Cyclamen, Echinacea, Epimedium, Euonymus, Fuchsia, Heuchera, Hosta, Hydrangea, Busy Lizzie, Kalmia, Lily, Peony, Phlox, Primula, Polyanthus, Raspberry, Rhododendron, Saxifrages, Sedum, Strawberry, Syringa, Yew and Wisteria.
Vine weevil damage
Adult vine weevils nibble on your plant leaves at night, but it’s actually the larvae that do most of the damage by eating your roots in the soil.
Vine weevil symptoms include:
- damage to leaves
- wilting plants
- grubs in your pots and soil
Vine weevil damage to leaves
The clearest sign of vine weevil damage is circular bites in your leaves.
The adult weevil bug eats your leaves, always starting from the edge to form semi-circle notches, and working their way inwards.
Vine weevil leaf damage
Their mouths don’t allow them to start biting in the middle of leaves, so if you see this it’s another pest, such as a caterpillar or slug.
Another common sign is wilting plants.
Wilting rhododendron due to vine weevil damage
This is a symptom that the vine weevil larvae are eating your roots, reducing the plant’s ability to take up water and nutrients.
It's a vague and often-missed symptom. You may think you’re simply not watering enough, but you should always check the roots for damage.
If your roots are being eaten, vine weevils are the source.
White grubs in plant pots and soil
You’ll also see white grubs in your garden pots, containers or soil if you dig around.
These larvae are small (just under 1cm), c-shaped and with distinctive small, pale-brown heads.
Vine weevil larvae image
Check for Vine weevil adults
If you suspect vine weevil, go check your plant at night and you should see them crawling around. They’ll likely play dead if you shine a torch on them.
During the day they hide under plant pots, in the bases, under benches, and a myriad of places.
Vine weevil adults
Vine weevils adults are:
- 1cm/half an inch in size.
- A dull-black colour
- Have a bumpy texture with orange dots
- V-shaped antennae
Their body is also pear-shaped from above, and clearly divided into two segments.
Vine weevil treatment UK
Nematodes gets rid of vine weevils organically.
Vine weevil nematodes are microscopic worms (0.3-1.1mm in length) that are natural parasites of vine weevil. They move through the soil by themselves, locate and infect the vine weevil larvae, killing it.
How nematodes kill vine weevil
They’re the best treatment for vine weevil, since it’s a safe, natural treatment with no chemicals.
It can be used on any plants without affecting them, including edible or ornamental plants growing in the ground (unlike insecticides).
Nematodes work for six weeks, but give up to four months since they prevent the larvae from hatching into adults and causing another lifecycle.
The only downside to nematodes is you have to store in the fridge before use, but that’s nothing too onerous.
- Store in the fridge before use
- Add packet to watering can with 1.5L of water and water the soil
- Keep the soil moist for two weeks
You can also use a vine weevil chemical control such as a spray.
Normal insecticide sprays don’t work on vine weevils in the soil, so a very strong pesticide type called a systemic neonicotinoid insecticide acetamiprid must be used.
They release nasty chemicals into the environment, and kill other wildlife.
- Sprays can only be used on ornamental plants in pots, NOT fruits, or even ornamental plants in the ground, because of the chemical damage.
- They give a similar protection time to nematodes, and you have to mix the contents with water (concentrations vary), but you don’t have to keep it in the fridge first.
- Ensure you drench the soil thoroughly. Sprays can’t move through the soil like nematodes. The insecticide then kills the vine weevil larvae via a chemical process.
- Be very careful when spraying, as you cannot breathe it in.
Vine weevil lifecycle
Vine weevil lifecycle diagram
The adult vine weevils eat your leaves between April and October, which gives it the energy to lay eggs.
Each adult lays around 500-600 eggs, and since all adults are female, they can all lay eggs. Fortunately, there is only one lifecycle per year.
They like to lay their eggs in the soil near the base of the plant.
The white C-shaped larvae then emerge into the soil from June and start to eat the roots of the plant. They can feed until October.
The larvae survive through the winter but stop feeding. They hibernate around the roots over winter, and then form pupae in April.
Some adult beetles also survive by finding sufficient places to shelter over winter, but again stop feeding until April.
What do vine weevil eggs look like
Eggs start off white, but turn brown before they hatch, making them very difficult to spot in soil.
It’s highly unlikely you’ll be able to see the vine weevil eggs in compost or soil as they’re so tiny - less than 1mm.
If you see clear eggs, these aren’t weevil, but slugs or snails.
Do weevils jump?
Yes, vine weevils jump down to plants from walls, particularly in greenhouses, to land near pots. That’s why it’s important to keep infested plants away from walls.
Black vine weevil
However, they can’t jump upwards, and they can’t fly. So if you see a bug doing either of these things, you’re looking at a different pest.
Vine weevil-resistant plants
Sick to the back teeth of dealing with vine weevil? Vine weevil adults prefer to munch on basic, odourless leaves, so you can try growing plants that break these rules.
Plants that vine weevils don’t like include:
- Fragrant herbs like mint, lavender and lemon balm
- Those with sticky/fragrant leaves, like Geranium macrorrhizum
- Those with furry leaves, like Stachys byzantina
Furry Stachys byzantina leaves
They also prefer plants in pots or containers, so try to stick to planting in soil where possible.
MightyNem® Vine Weevil Nematodes 10 sq m
Pack of 5 million nematodes to control vine weevil larvae. Free next day delivery.
MightyNem® Vine Weevil Nematodes 100 sq m
Pack of 50 million nematodes to control vine weevil larvae. Free next day delivery.