Emerald Ash Borer

The Emerald Ash Borer (EAB) is a small, metallic green beetle that feeds on the wood of ash trees. Once introduced, the invasive pest can destroy and kill an ash tree within three to five years. According to the City of Madison Parks Division, in late March 2018 the entire state was placed under quarantine for EAB. Ash trees that are infested with EAB quickly become hazardous and should be removed by qualified tree workers.

Signs of EAB

Ash tree showing increased woodpecker activity.

Ash tree showing increased woodpecker activity.

ISA Certified Arborists and MGE tree pruning crews are looking for signs of EAB while we are working in local neighborhoods. While EAB could destroy an ash tree quickly, signs and symptoms may not appear for more than two years. It should be assumed, however, that all ash trees within 15 miles of a known infestation are affected.

Signs and symptoms of EAB infestation include:

  • Dead branches throughout the canopy beginning at the top and/or new branches growing at the base of the trunk.
  • Vertical splitting, D-shaped holes and S-shaped patterns in the bark.
  • Increased woodpecker activity or damage.

Treatment of EAB

EAB is 100% fatal to an untreated ash tree. Insecticide treatments are available to prevent EAB from killing ash trees if detected in the early stages. We recommend contacting an ISA Certified Arborist for more information on how to properly treat or remove ash trees.

Prevention of EAB

EAB can continue to emerge from wood from affected ash trees for two years after cutting. To avoid spreading EAB, follow Wisconsin guidelines for firewood movement.

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