Skip to Main navigation Skip to Left navigation Skip to Main content Skip to Footer

University of Minnesota Extension
www.extension.umn.edu
612-624-1222

Extension > Garden > Diagnose a problem > What's wrong with my plant? > Deciduous Trees > Mountain Ash > Holes in leaves or parts of leaves missing

Print Icon Email Icon Share Icon

Mountain Ash > Leaves > Holes in leaves or parts of leaves missing

1 of 2
  • Image: Mountain ash sawfly 1
  • Image: Mountain ash sawfly 2
  • Image: Mountain ash sawfly 3

Mountain ash sawfly
Pristiphora geniculata

  • Feed in groups, consuming all of leaf except the mid-vein
  • Larvae defoliate one branch at a time
  • Larvae are ½- ¾ inch long, light greenish yellow with black spots
  • Active from mid-June to early August and again from late August to September
  • More information on Mountain ash sawfly...
2 of 2
  • Image: Japanese beetle 1
  • Image: Japanese beetle 2
  • Image: Japanese beetle 3

Japanese beetle
Popillia japonica

  • Skeletonizes leaves, i.e. chews leaf tissue between the veins creating a lacelike appearance
  • Attacks are common in sunny locations starting at the top of the plant and working down as they feed
  • Adults are metallic green; bronze wings; white tufts of "hair" along their sides
  • Beetles present as early as late June and are active through September
  • More information on Japanese beetle...

Don't see what you're looking for?

  • © Regents of the University of Minnesota. All rights reserved.
  • The University of Minnesota is an equal opportunity educator and employer. Privacy