Vine Weevil

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PestControlBasics Editorial Team

Reviewed by Derek Giordano · Updated 2026

Illustrated identification guide — PestControlBasics.com

🔍 Identification

Adults: 8-10mm; dull black with yellowish-grey flecks; cannot fly; distinctive elbowed antennae; all individuals are female (parthenogenetic — no males). Found feeding on leaves at night. Leaf damage: distinctive semicircular notches along leaf margins — diagnostic. Grubs: C-shaped; cream-white; legless-looking; found in potting soil around root zones.

🧬 Biology & Behavior

Vine weevil is a significant pest of container plants including: rhododendron, azalea, camellia, strawberry, Heuchera, cyclamen, and many others. Adults lay hundreds of eggs in potting soil from July through October. Grubs hatch and feed on roots through fall and winter, killing plants from below. All adults are female — no males needed for reproduction, making population control challenging.

⚠️ Damage & Health Risk

Complete root destruction killing container plants; collapse of seemingly healthy plants with no warning; economic losses in commercial nursery production.

🔧 DIY Treatment

Beneficial nematodes (Steinernema kraussei or Heterorhabditis megidis) watered into potting soil in September is the most effective organic management. Apply when soil temperature is above 41°F. Sticky barriers around pot rims reduce adult access. Inspect root zones of new container plants before purchase.

👷 When to Call a Pro

Commercial nursery: nemasys/steinernema applications in August-September plus sticky traps and barrier programs at high-value container crop sites.

❓ FAQ

When should I apply nematodes for vine weevil?

September is the optimal window — soil temperatures are still above 41°F but new grub hatch is in early instars (most susceptible to nematode infection). Ensure soil is moist before and after application. Nematodes are killed by UV light — apply in evening and water in immediately. Keep soil moist for 2 weeks after application.

How do I know if vine weevil killed my plant?

If a container plant suddenly wilts despite adequate water, tip it out of the pot. If the root ball is destroyed or largely absent and you find white C-shaped grubs in the potting mix, vine weevil grubs are confirmed. Healthy roots are white and firm; vine weevil damage leaves no roots at all in the feeding zone.

🪲 Vine Weevil