How to Combat Vine Weevils

Because of their small size and the fact that they are nocturnal, you may not even be aware that you have a problem with vine weevils. You may be in the garden one day and your plants are healthy and then you wake up the next day and your healthy plants will be wilting or even dying.

Further investigations may then reveal that your plants have fallen victim to an infestation of vine weevil larvae who have eaten away all of the roots of your plants or the adults will have eaten the leaves so how can you tell you’ve got a vine weevil problem and what can you do to combat it?

The Telltale Signs of the Presence of Vine Weevils

The keener you are at tendering your plants, the quicker you will be able to spot signs of the vine weevil. They will attack the roots of almost any plant but they are particularly attracted to primulas and cyclamen such as azaleas, rhododendron, fuchsias and yew. The signs that they are present include notches in leaves that are C-shaped and plants whose leaves start to wilt and turn yellow.

What is the Best Way to Prevent and Control Them?

If you go out and look at the leaves of the plants at night with a torch, you might actually see the vine weevils feeding off the leaves as they are nocturnal creatures which come out to eat at night. You can then simply knock them off into a container and kill them using some form of biological control or by applying a pesticide to the leaves that contains Imidacloprid. Your garden centre should be able to advise you on this.

One of the key methods of prevention in the first place is to begin at the roots as the vine weevil cannot fly. Instead it crawls up plants until it reaches the leaves. The larvae can cause even more damage to the roots but by sprinkling a layer of grit thickly around the plants that are affected, this deters the adults from laying eggs there. Of course, by then, it may be too late to save the plants which have been affected.

Controlling the Vine Weevil Organically

If you’re an organic gardener and prefer not to use chemicals or pesticides in your garden, introducing beneficial nematodes into the soil which you can buy from good garden centres will go after the larvae in the soil which is a way of controlling them safely and naturally.

Understanding the Life Cycle of the Vine Weevil

By understanding the life cycle of the vine weevil and being able to identify both an adult vine weevil and the larvae, it will greatly improve your chances of keeping this pest at bay. All adult vine weevils are female and will tend to emerge from the soil in late Spring when it will look to feed for 4 to 5 weeks in order to produce in excess of 300 eggs and up to as many as 1,000 which it will lay at the root of the plant.

Adult vine weevils are around half an inch long, oval shaped and coloured matt black with yellowish flecks. The eggs are creamy or off-white in colour at first which later turns brown and they hatch within 2 weeks of being laid. The larvae that emerge are about 12mm long and have a tan head and creamy coloured body. They will then tunnel deeper into the soil and begin feeding off the roots of the plant, digging themselves in ever deeper until they go into a resting period (pupae) and then they’ll emerge from the soil after around 6 months as fully-fledged adults.

By understanding the life cycle of the vine weevil, prevention in the first place is far better than trying to instigate a cure for your plants later because if they get hold of a particular plant, they can wreak havoc within a short space of time and by then, your plants may already have been damaged beyond repair.