Vine Weevil Control: How to Get Rid of Vine Weevils in Your Garden As the gardening season nears, gardeners everywhere are concerned about a wide range of pests. Pests like black vine weevils, which damage plants, consume blooms and even kill vegetation from the ground up, are a particular problem in landscapes. It’s possible to deal with black vine weevil damage if you’re well-informed on the pest.
About Black Vine Weevils
More than a hundred types of ornamental plants are targeted by black vine weevils (Otiorhynchus sulcatus) in the United States, including rhododendrons, azaleas, pine trees and evergreen trees. The damage weevils may do to begonias, ferns, and other popular indoor plants depends on how they got into your house, greenhouse, or indoor garden.
A common nickname for them is the “cyclamen grub,” because of the damage they cause to cyclamens. More than a hundred varieties of host plants are available to the black vine weevil, however they prefer the following: Yew Hemlock Rhododendrons A laurel from Azalea Mountains Euonymus Grapes from the Japanese holly Liquidambar While the strawberry root weevil is only about half an inch (1.3 cm.) long, these beetles are twice as large and may be impossible to tell apart from other members of their family with the naked eye.
There is, however, a good possibility that black vine weevils are to blame if you have damaged yews nearby. Detecting the adult form isn’t difficult, but it’s the larvae that pose the greatest threat to the ecosystem. Black vine weevils are tough to get rid of because they burrow into the earth and feed on the roots they find. When soil moisture brings the grub-like pests closer to the surface, where they may happily girdle plants and munch bark, larval feeding damage is usually worse in the spring.
Black Vine Weevil Control
If you catch mature black vine weevils feeding in your garden, defeating them isn’t too tough. Adults typically lay eggs after 21 to 28 days of eating, therefore your initial goal should be to kill them before this occurs. Hand-picking black vine weevils is one of the safest, although time-consuming, ways to get rid of a significant number of the pests.
Use a flashlight to find them at dusk, and then submerge all of your unfortunate victims in a pail of soapy water. Whether you haven’t managed to catch all of the weevils with hand-picking and your plant is still suffering, it’s time to see if there’s anything else that can get rid of black vine weevils. Nematodes are the answer to that query! For black vine weevils, Heterorhabditis spp. are recommended because of their relative mobility and inclination to dig deeper in the soil for prey.
When using nematodes, make sure to follow the instructions on the package. Make sure to retreat a week or two after the first injection to allow the nematode colony to better establish itself.
- Get rid of mulch and other hiding places around your plants. Only water your plants when necessary (larvae and adults prefer moist soil).
- Weevils are non-flying insects, thus they travel by walking. Tanglefoot Sticky Barrier should be the initial line of defense, as this is logical.
- To keep pests at bay for the long haul, use organic Diatomaceous Earth. Tiny fossilized aquatic organisms are what make up DE, and when an insect comes into contact with it, the powder cuts into its outer coat. This product is completely free of chemicals that are harmful to humans.
- In potted plants, the black vine weevil’s immature stages are particularly sensitive to helpful nematodes.
- Beauveria bassiana in BotaniGard ES is an entomopathogenic fungus that attacks a lengthy range of difficult pests, including resistant forms. BotaniGard ES is an extremely powerful biological insecticide. Insect population explosions can be prevented and pesticide protection similar to or greater than conventional chemical pesticides can be achieved with weekly applications.
- To keep adult weevils out of buildings, apply fast-acting crack and crevice sprays like Don’t Bug Me around windows, doors, and vents.
- Botanical insecticides should be used only as a last option. Natural pesticides, which are derived from plants with insecticidal qualities, have fewer adverse side effects and break down more quickly in the environment than synthetic ones.
Using burlap to trap weevils at the base of trees and shrubs is a good idea.
The nearly-grown larvae of black vine weevils overwinter in the soil around the roots of their host plants. Pupae emerge as adults in the spring after their winter hibernation. They begin depositing eggs around the host plants’ crowns in two or more weeks, depending on the weather. It takes roughly ten days for a butterfly’s eggs to hatch and for the small larvae to begin feeding. Every year, a new generation is born.