One dose isn’t usually enough to get good results, so make sure you retreat a week or two later to help the nematode colony better establish itself. A minimum period of six weeks should be observed after initial application before any subsequent treatments of Pitcher or beneficial parasitic nematodes can be applied. Adult weevils will crawl into the folds of the cloth to hide during the day. Black Vine Weevil beetle (Otiorhynchus sulcatus) aka: Taxus weevil is a very serious pest both landscape plantings and in nursery and greenhouse settings.The larvae feed on the roots of plants and are especially fond of hemlock types of plants. In the United States, black vine weevils were first noted in 1835 in Massachusetts. If controls are needed, they can be directed at the adults to kill them before they lay eggs. I got this from internet research, too, from the RHS forum 2005. If you catch black vine weevil adults feeding in your garden, they’re not all that difficult to defeat while their numbers are still low. Find more gardening information on Gardening Know How: Keep up to date with all that's happening in and around the garden. The University of Connecticut, Cooperative Extension System, College of Agriculture and Natural Resources is an equal opportunity program provider and employer. Larger roots and the crown may be girdled (removal of the bark in a ring) resulting in wilting, yellowing of the foliage, and possible death of the plant. Adult vine weevils are about 10 to 12mm long and are brown/black with faint yellow spots. Hand-picking is one of the safest, though tedious, ways of eliminating large numbers of black vine weevils. Peggy Greb, USDA Agricultural Research Service,, Weevils On Sago Palms – How To Control Palm Weevils, What Are Hollyhock Weevils: Alleviating Hollyhock Weevil Damage, What Are Rose Weevils: Tips For Controlling Fuller Rose Beetle Pests, DIY Lemongrass Tea: How To Make Lemongrass Tea, What Is Weed Tea – Making Fertilizer From Weeds, Plants For Veterans – Honoring Veterans With Flowers, Hydroponic Water Temperature: What Is The Ideal Water Temp For Hydroponics, Planting Seeds Outside – Tips On When And How To Direct Sow Seeds, Compass Plant Information: Tips On Compass Plant Uses In Gardens, DIY Plant Rescue: Finding And Bringing Plants Indoors, Winter Crafting Ideas: My Top Craft Projects For Fall And Winter, Creating A Terrarium To Beat Winter Blues, Epic Garden Fail: DIY Raised Beds From Hell. Larval feeding damage tends to be worst in the spring, when soil moisture drives the grub-like pests closer to the surface where they’ll happily girdle plants and chew bark. They have one generation per year (more if in a greenhouse). It is approved through an Extension of Authorisation for Minor Use (EAMU) in containerised ornamental plants, both protected and outdoors. Any reference to commercial products, trade or brand names is for information only, and no endorsement or approval is intended. Many infestations of black vine weevil occur as a result of purchasing infested plants. As gardening season draws ever nearer, all manner of bugs are on the mind of growers everywhere. The 5/8-inch weevils are black with gold flecking on the wing covers (elytra). If your plants are heavily mulched, pull back this mulch to allow the surface of the soil to dry out and do not water plants unless necessary. Therefore, if insecticide treatments for adults are used they should be applied beginning in mid- to late-June. Damage . If weevils are found only in certain areas of a field or nursery, growers should consider applying spot treatments if using insecticides. The Cooperative Extension System does not guarantee or warrant the standard of any product referenced or imply approval of the product to the exclusion of others which also may be available. Plants showing signs of adult feeding should not be purchased because larvae may be in the soil of the root ball. Made by Fuse. However, if you’ve got damaged yews nearby, the chances are good that you’re dealing with black vine weevils. Black vine weevil damage can be extensive, but they can be managed if you’ve got enough black vine weevil information. The traps can be inspected by gently removing the burlap and examining it for weevils. The adult is 3/8 to 1/2 inches long, shiny, black, female, and cannot fly. It generally takes 21 to 28 days of feeding before they’re ready to lay eggs, so your first goal is to kill the adults before this happens. Exemptor is also available for us in peat and non-peat based growing media. The information in this document is for educational purposes only. Updated by Donna Ellis, Senior Extension Educator, UConn IPM Program, 2011. Disclaimer. This accounts for their other common name, elephant beetle. Pitcher is not affected by temperature fluctuations unlike some other biological products. When you know you’ve not caught all the weevils by hand-picking or your plant continues to suffer despite your efforts, it might be time to look into what kills black vine weevils besides human hands. Since they burrow in the soil and feed on roots underground, getting rid of black vine weevils can be difficult. This suggests it would kill vine weevil grubs and harm anything that ate them.