Otiorhynchus spp. and other species

Photo courtesy of the Oregon Department of Agriculture.

Signs & Symptoms

Photo by Chal Landgren, OSU.

  • Reduced plant growth
  • Yellow needles and premature needle loss and/or root damage
  • Scalloping or notching along needle margins
  • Legless larvae grubs that bend their bodies in the shape of the letter “C”

Where to Look

Photo by Chal Landgren, OSU.

  • New fields
  • Field edges

Similar Symptoms As

Photo courtesy of Ken Gray Insect Image Collection, OSU.

  • Root problems
  • Environmental stress


  • Monitor for adult weevils beginning in late May and early June, especially under needles, on cloudy days and in the evening.
  • Scout for larvae on the roots of host plants April to May.

Management Options

  • At the first appearance of adults, apply chemical control and repeat.
  • In the summer and fall, use habitat disruption practices such as disking or tilling, which may reduce populations.

Host Susceptibility

host susceptibility graph

  • High susceptibility: Douglas-fir, Noble fir
  • Medium susceptibility: Grand fir
  • Low susceptibility: Nordmann fir, Turkish fir

Management Calendar

  • Look for notched needles: June through October
  • Look for Larvae: April through May
  • Look for adults June through September
  • Use biocontrol: April through May
  • Spray foliar insecticide (if needed): Mid-June through Mid-August
  • Prepare the site: Mid-August through Mid-October