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Polydrusus Weevils

Polydrusus formosus and P. impressifrons[5]

Polydrusus weevils are small introduced weevils covered with iridescent green scales that feed on tree and shrub leaves in summer.[1][2][3]

Group
Insect
Order
Coleoptera
Family
Curculionidae
US records
18 states
Sources
5 cited
Updated
2026-10-16
Polydrusus weevil covered in iridescent green scales on a leaf
Polydrusus weevil covered in iridescent green scales on a leaf. (c) Darren Obbard, some rights reserved (CC BY) — via iNaturalist, CC BY 4.0
On this page
  1. Identification
  2. Where it lives
  3. Biology
  4. Damage and signs
  5. Health risk
  6. Control
  7. Related profiles
  8. Common questions
  9. Sources

How to identify it

  • Adults are slender, about 1/4 inch long, with a short blunt snout and a dark body covered in bright green, iridescent scales; where scales rub off they look green with black patches.[1][2][3]
  • UMass notes two introduced species in the Northeast: P. formosus, 0.2 to 0.27 inch long, and the smaller P. impressifrons, 0.15 to 0.22 inch.[1]

Where it lives

Both species came from Europe in the early 1900s and occur in the northeastern United States; P. impressifrons is common in forested northeastern and north-central Minnesota.[1][2]

US map: public records from 18 states since 1990 (GBIF).

Biology and life cycle

There is one generation a year: adults emerge from the soil in late May or June and feed until August.[1][2][3]

Females lay groups of tiny white eggs on the soil or in bark crevices; the larvae feed on roots, overwinter there and pupate in spring.[1][2]

Damage and signs

  • Adults chew the leaves and buds of birch, poplar, willow, apple, rose, strawberry and other trees and shrubs, and young trees can show noticeable feeding.[1][2][3]
  • Damage is usually cosmetic, and root feeding by the larvae is not thought to cause significant harm.[1][2][3]

Health risk

Harmless to people and property, though weevils that wander indoors from June through August are a nuisance.[2][4]

Control

Keep them out

Caulk cracks and keep screens and doors snug to keep weevils out of the house.[2]

Traps and physical control

Vacuum or sweep up weevils found indoors; they are temporary and go away on their own.[2]

Pesticides

Pesticides are generally not needed, and products sold to the public are not very effective against weevils.[2]

Common questions

What are the tiny shiny green weevils in my house?
Often Polydrusus weevils, which wander in from June through August and are harmless.[2][4]
Do Polydrusus weevils damage trees?
Rarely seriously; feeding is usually cosmetic, though young trees can show noticeable damage.[1][3]

Sources

  1. UMass Extension Landscape, Nursery and Urban Forestry Program (Landscape Insect & Mite Guide), “Polydrusus spp. (Polydrusus Weevil).” www.umass.edu/agriculture-food-environment/landscape/publications-resources/insect-mite-guide/polydrusus-spp (accessed 2026-10-16)
  2. University of Minnesota Extension, “Home-invading weevils (Nuisance Insects).” extension.umn.edu/nuisance-insects/home-invading-weevils (accessed 2026-10-16)
  3. University of Minnesota Extension (What insect is this?), “Polydrusus weevil (garden pests).” apps.extension.umn.edu/garden/diagnose/insect/garden/beetles/medium/polydweevil.html (accessed 2026-10-16)
  4. University of Minnesota Extension (What insect is this?), “Polydrusus weevil (insects found indoors).” apps.extension.umn.edu/garden/diagnose/insect/indoor/beetles/medium/polydrususweevil.html (accessed 2026-10-16)
  5. iNaturalist, “Polydrusus formosus taxon page (order and family).” www.inaturalist.org/taxa/494559 (accessed 2026-10-06)

Updated 2026-10-16. Built from sourced records. Spot an error? Tell us.