Mindarus abietinus

Photo by Rayanne D. Lehman, Pennsylvania Dept. Agriculture (PDA).

Signs & Symptoms

Photo by Chal Landgren, OSU.

  • Curled, twisted needles on current year’s growth
  • Stunted needles
  • Needle loss
  • Black, sooty mold on stems, trunk, and needles
  • Presence of bees and/or yellow jackets

Where to Look

  • Localized areas in the field

Similar Symptoms As

  • Various aphid species


  • Monitor egg hatch by late April, using a hand lens (15x). Aphids have two distinct forms: stem mother is relatively large and bluish-gray; offspring is smaller, greenish-yellow, and may be covered by a fine powdery wax.
  • Scout for pale tan, oval eggs coated with wax.
  • Use beating sheet or board to detect presence of adults.
  • Listen for wasps and bees.
  • Check for black soot on the ground.

Management Options

  • Encourage natural predators like lacewings, earwigs, lady beetles and their larvae, ants, predatory thrips, predaceous midges, and parasitoids such as Aphidius spp.
  • Apply insecticide after eggs hatch. Synthetic pyrethroids may cause outbreak of secondary pests, such as eriophyid mites, due to reduction of natural predators.

Host Susceptibility

host susceptibility graph

  • High susceptibility: Balsam fir, Fraser fir
  • Medium susceptibility: Grand fir, Noble fir
  • Low susceptibility: White fir

Management Calendar

  • Look for needle distortion, stunting, and loss: Mid-May through Mid-November
  • Look for presence of adults: Mid-March through June
  • Spray insecticide (if needed): April through Mid-August