What's wrong with my plant? Give us your feedback

Elm > Trunk/Branches > Holes in trunk or branches

1 of 4
  • Image: Native elm bark beetle 1
    Credit: D. Hanson, University Of Minnesota
  • Image: Native elm bark beetle 2

    Credit: R.J. Stipes, Virginia Tech., Bugwood.org

  • Image: Native elm bark beetle 3

    Credit: J. O'Brien, USDA Forest Service, Bugwood.org

  • - CLICK PHOTOS TO ENLARGE -

green arrowNative elm bark beetle
Hylurgopinus rufipes

  • Egg galleries extend against grain, noticeable when bark is removed
  • Little or no damage to tree unless beetle is carrying Dutch elm disease fungal spores
  • Adults are 3/32 inch long; brownish black
  • All elm species in Minnesota are attacked
2 of 4
  • Image: European elm bark beetle 1
    Credit: J. LaForest, University of Georgia, Bugwood.org
  • Image: European elm bark beetle 2

    Credit: R.S. Cameron, Advanced Forest Protection, Inc., Bugwood.org

  • Image: European elm bark beetle 3

    Credit: M. Jurc, University of Ljubljana, Bugwood.org

  • - CLICK PHOTOS TO ENLARGE -

green arrowEuropean elm bark beetle
Scolytus multistriatus

  • Feed at the twig crotches, girdle the bark, cause small branches to fall off
  • Egg galleries extend with the grain, noticeable when bark is removed
  • Little or no damage to tree unless beetle is carrying Dutch elm disease fungal spores
  • Adults are 1/8 inch long; shiny, dark reddish brown to black
  • All elm species in Minnesota are attacked
  • More information on European elm bark beetle...
3 of 4
  • Image: Woodpeckers 1
    Credit: J. Johnson, Georgia Forestry Commission, Bugwood.org
  • Image: Woodpeckers 2

    Credit: D. Hanson, University of Minnesota

  • Image: Woodpeckers 3

    Credit: S. Katovich, USDA Forest Service, Bugwood.org

  • - CLICK PHOTOS TO ENLARGE -

green arrowWoodpeckers

  • Holes are round and range in size from 1/4 to 1/2 inch
  • Larger holes, 1 1/2 or more inches may be nesting holes and suggest softer heartwood inside the tree
  • Bark often removed around holes
  • Woodpecker probing may indicate presence of wood boring insects under bark
  • Repetitive tapping or drumming heard
  • Birds of varying black and white patterns, often with some red, seen tapping on trees
  • More information on Woodpeckers...
4 of 4
  • Image: Carpenterworms 1
    Credit: J. Solomon, USDA Forest Service, Bugwood.org
  • Image: Carpenterworms 2

    Credit: J. Solomon, USDA Forest Service, Bugwood.org

  • Image: Carpenterworms 3

    Credit: J. Hahn, University of Minnesota

  • - CLICK PHOTOS TO ENLARGE -

green arrowCarpenterworms
Prionoxystus robiniae

  • Exit holes in wood are round and large, about 1/2 inches
  • Galleries start in sapwood, eventually entering heartwood
  • Large amount of sawdust in piles present at trunk base
  • Stout bodied moths, black and light gray mottled forewings as large as 2 1/2 to 3 inches
  • Yellowish white caterpillars with brown heads; 2 to 3 inches long
  • More information on Carpenterworms...

Don't see what you're looking for?