Pesteleminater Log

Black vine weevils: Control and prevention

Black vine weevil on a leaf

Black vine weevils can cause a great deal of damage to plants in private gardens, they are also a great danger to plants and crops in agriculture. Plants attacked by black vine weevils are more susceptible to attacks from other pests since the weevils will weaken the plant's ability to fight other pests. In most cases, this will end up killing the plant. Damage to the leaves of the plant will often be observed, but the real damage caused by weevils is to the roots of the plant.

Black vine weevils as a pest

Adult black vine weevils will seldom cause serious issues, but the sight of bite marks in the leaves of a plant can appear unsightly. The real damage comes from the larvae, that reside near, and feeds on the root system of an affected plant. This will in time kill an affected plant, with most death occurring in March or September when the larvae begin to hatch and grow.

The spread of weevils can almost always be attributed to human activities. Firstly through the international trade of plants and soil, and then, secondarily, on a local level between shops and customers or among private individuals trading and selling plants, soil, and garden equipment amongst themselves. Because weevils lack the capability to fly, they need the help of humans to spread over larger distances.

Black vine weevils are quite opportunistic when it comes to which plants they attack. Some of these plants include Rhododendrons, grapes, and strawberries. They will for the most part target herbaceous and woody garden plants, while they will at times target ornamental shrubs and plants. Plants that have leaves all year round will get targeted more often, than plants that shed their leaves during winter. It is important to note, that plants in pots are a more prized target for black vine weevils, and they will seldom target plants growing in loose soil in the garden.

Adult beetles eating the edges of leaves will rarely result in the plant dying or even taking damage, but it can make the plant appear unsightly. However, the larvae will absolutely be a danger to the health of the plant. They eat away at the roots, and in many cases, the plant will die.

5 ways to identify a black vine weevil infestation

Identifying a weevil infestation can be very difficult since the damage caused by weevils can be misidentified as coming from other insects. Furthermore, weevils are active at night, so you might not even get the chance to spot them yourself.

  1. Look for jagged edges on leaves: since adult black vine weevils eat the leaves the edge in, the leave will appear to have jagged marks on the edges. 
  2. Shake adult beetles out of the plant: place a piece of white paper under the plant, and shake the plant. The weevils will fall out and hit the white paper, making them easier to see with the naked eye.
  3. Look for larvae in the soil: black vine weevil larvae will appear as small larvae crawling around the root system of a plant. Take the plant out of the pot, and look for the larvae.
  4. Check plants that are dying: If you have any plants, that appear to be going through a rough time, it would be a great idea to check the root system for weevil larvae. You might never now wether or not a plant dying is caused by weevils.
  5. Use sticky traps to catch them: Sticky traps can be positioned around the base of the plant. This will trap any weevil trying to climb the plant.

Prevent black vine weevils from infesting your plants

While it is impossible to completely prevent the occurrence of weevils, there are some things you can do, to minimize the risk of them infesting your plants. Here are some preventative measures you can take, to prevent the occurrence of black vine weevils. 

  • If you bring new plants or soil to your property, check the dirt and plant for weevils.
  • Remove hidden larvae from the roots by washing the dirt away with a garden hose.
  • Make sure your plants are in great condition with all the nutrition they need. This will help them fight off attacks from weevils.
  • Set up sticky traps around the base of susceptible plants.
  • Use nematodes preemptively. Nematodes are small roundworms, that infects and kills a great variety of insect and slugs.

Get rid of black vine weevils

Weevils are not the easiest pest to get rid of. They are only active at night, so you will probably never even get a glimpse of them. You will need resilience and cunning to get rid of the weevils, and here are some of the methods, you can use to control them:

  • Weevil infestations can be reduced in severity with the use of sticky traps. Black vine weevils, can be captured using so-called glue rings or glue strips that are attached to the base of the plant. When the weevils venture out at night to look for food, they will climb the core of the plant, and trap themselves.
  • It is possible to capture weevils yourself. This will need to be done at night when the weevils are active and out looking for food. Spread out something that can capture falling weevils under the plant, and start shaking it. The weevils will fall out of the plant and be captured. Alternatively, you can use a vacuum cleaner to, very carefully, hoover the weevils out of the plant
  • Nematodes can be used to kill both adult and larvae weevils. Nematodes are spread in the soil in your garden, and the roundworms will then begin to infect insects and slugs in your garden, ultimately killing them. Nematodes are a great way to deal with weevils, since they target not only weevils but also a lot of other pests, that can infest your garden.
  • You can also use organic insect spray to kill weevils. Spray directly on visible weevils, or spray it on plants that are in danger of being attacked by weevils.
  • If no adult weevils are present, and you are only bothered by the larvae, you can replace the dirt in the pot. Remove the plant from the pot, wash the dirt of the roots, empty the pot and fill it with new dirt

Facts about Black vine weevils

Worldwide, there have been found up to 97,000 different species of weevils, but together with the strawberry root weevil (Otiorhynchus ovatus) the black vine weevil is one of the more inconvenient and damaging weevils to plants. Black vine weevils belong to the genus Otiorhynchus, which contains 1,500 species of weevils. Most of the species of weevil in Otiorhynchus are parthenogenetic, meaning they can reproduce without the need for a mate. This can result in pest infestations that grow at a rapid rate, and a single black vine weevil can create infestations of epic proportions if left unchecked.


Weevils are small beetles that have an elongated head, that is sometimes referred to as a snout. Most species of weevils have the ability to retract their antennae, which will lay flush with the head, and protect the beetle when burrowing.

The length of the black vine weevil ranges between 9 and 11 millimeters. Black vine weevils are (as the name indicates) black, with golden hair growing in patches across the fused elytron (wing covers).

Behavior, lifestyle, and reproduction

Since the beetle's wing covers are fused together, it is not able to fly. It will crawl out of the dirt at night, and feed on the outer edges of a plant’s leaves, which will leave notches.

Even though black vine weevils are technically capable of producing male offspring by fertilizing eggs, no male black vine weevils have ever been observed. The larvae are found in soil, where they feed on the root systems of the plants. They reach a length of approximately 10 millimeters, have a body that is slightly bent, do not have legs, and are a milky yellow color with a brownish head. A female can lay up to several hundred eggs in a single season.

Black vine weevils are native to Europe but have spread to the American continent through the trade of plants and soil.

Frequently asked questions: Black weevils

What are black vine weevils?

Black vine weevils are small, black insects with elongated bodies and curved antennae. They are known to feed on the foliage and roots of a wide variety of plants, including roses, rhododendrons, and fruit trees.

How can I tell if my plants have been infested by black vine weevils?

There are several signs that your plants may be infested with black vine weevils, including notched or jagged edges on the leaves, yellowing or wilting of the leaves, stunted plant growth, and the presence of small, black insects on the plants or in the soil.

How can I control black vine weevils in my garden?

To control black vine weevils in your garden, you can try the following methods: handpicking and removing any weevils you see from your plants, using a chemical insecticide specifically formulated to control weevils (be sure to follow the instructions carefully and apply the insecticide according to the label directions), using a biological control such as nematodes, which are small worms that can kill the weevils, and cultivating the soil around your plants to expose the weevils to birds and other predators.

How can I prevent black vine weevils from infesting my plants?

To prevent black vine weevils from infesting your plants, you can try planting resistant varieties of plants, keeping your garden clean and free of debris which can provide hiding places for the weevils, removing and destroying any infested plants to prevent the weevils from spreading, and using a chemical insecticide specifically formulated to prevent weevils (be sure to follow the instructions carefully and apply the insecticide according to the label directions).

Can I use natural methods to control or prevent black vine weevils?

Yes, there are several natural methods you can use to control or prevent black vine weevils, including handpicking and removing any weevils you see from your plants, using a biological control such as nematodes, cultivating the soil around your plants to expose the weevils to birds and other predators, and planting slug-repelling plants such as alliums or fennel around the perimeter of your garden to discourage the weevils from entering.

Pesteleminater Log
Pesteleminator is a website that offers tips and information on pest control and prevention. We provide articles and infographics to help educate people on the best practices for keeping their properties free of pests, including insects and rodents. Whether you are dealing with an infestation or just want to take proactive steps to prevent pests, Pesteleminator has something for you.