Elm Leaf Beetle

Xanthogaleruca luteola

Argentine Ant

Elm leaf beetle (Joseph Berger, Bugwood.org)

Argnetine ant bait trail

Elm leaf beetle damage (Whitney Cranshaw, Colorado State University, Bugwood.org)

Foraging Trail

Elm leaf beetle larvae (Pest and Diseases Image Library, Bugwood.org)

Identification

larvae:

  • yellowish in color with the appearance of black stripes in later stages

adults:

  • 3/16 - 1/4 inch long
  • yellow with black stripes/markings
  • black stripe along the edge of each wing cover
  • oval, soft-bodied insects

Nesting Habits

  • outdoors: live in elm trees on leaves and under bark and leaf litter at the base of the tree; woodpiles
  • indoors: garages; behind curtains, between books, under carpets, in wall voids, ventilators or other protected places

Diet

  • elm leaves

Significance

  • enter buildings in large numbers to overwinter or occasionally to escape hot, dry weather
  • larvae skeletonize leaves and defoliate elm trees
  • adults chew holes in leaves

IPM Recommendations

  • Use a vacuum to remove beetles indoors.
  • Do not attempt to kill these beetles in wall voids with insecticides unless they will be removed.┬áDead insects attract other pests. Instead, wait until summer to take exclusionary control measures.
  • Find and seal all exterior cracks in June or July and repair screens and door sweeps to prevent entry.
  • Keep elm trees healthy;┬átarget pesticide treatments at larvae and adult beetles on host trees.