Japanese Beetle (Popillia japonica) Population Discovered in Washington County

The Oregon Department of Agriculture (ODA) has detected an active population of Japanese beetles in the Cedar Mill area of Washington County. This insect is a major plant pest that is destructive to approximately 300 species of turf, fruits, vegetables, shrubs, and trees.

Because of the highly visible damage Japanese beetles cause to turf and ornamentals, the overuse of chemical controls is a real concern. ODA, along with partner organizations, has plans in place to limit and control the spread of this destructive, invasive beetle.

If you suspect that you have an infestation, do not apply pesticides yourself. Instead, call the Oregon Invasives Hotline at 1-866-INVADER to report Japanese beetle.
 

Leaf damage from Japanese Beetles (Steven Katovich, USDA Forest Service, bugwood.org)

Leaf damage from Japanese Beetles (Steven Katovich, USDA Forest Service, bugwood.org)

 

 

 

 

 

Japanese Beetles feeding on roses: flickr.com/photos/georgesgewels/2643035643/, Adult on flower: Kevin D Arvin, forestryimages.org.

Japanese Beetles feeding on roses: flickr.com/photos/georgesgewels/2643035643/, Adult on flower: Kevin D Arvin, forestryimages.org.

The following is a list of trees favored by Japanese beetle, though they are unlikely to kill a medium to large-sized tree:

  • American mountain-ash
  •  Apple, crabapple
  • Beech
  • Birch
  •  Black walnut
  • Cherry
  • Crape myrtle
  • Elm
  •  Holly
  •  Horse chestnut
  • Larch
  • Linden
  •  Maple
  •  Oak
  • Peach, apricot
  • Plum
  • Poplars/cottonwood
  •  Sassafrass
  • Western red cedar, arborvitae  
  •  Willow