Issue 7, June 16, 2014

Emerald Ash Borer Activity

Degree day accumulations have reached levels where we would expect adult emerald ash borer activity in infested areas of the state.

There are several metallic green beetles that are seen every day during the summer months. Several are commonly confused with the emerald ash borer. The two I most commonly receive calls and questions about are the Japanese Beetle and the six spotted tiger beetle. Both are similar in size to the emerald
ash borer, which is about 3/8 – 5/8 inch long. The Japanese beetle is rounder in its shape, and has bronze coloration on its elytra as well as that metallic green sheen. The six spotted tiger beetle is close to the emerald ash borer in size and shape, but has six white spots on its elytra. For more information on these and more look-alikes, check out these links:

Native Borers and Emerald Ash Borer Look-alikes (Adobe PDF)

Don't be Fooled by Look-Alikes (Adobe PDF)

Other signs and symptoms to look for in potentially infested ash trees:

  • Canopy dieback (begins in the top 1/3 of the canopy, progresses until the tree is bare.
  • Epicormic shoots (sprouts grow from the roots and trunk, leaves often larger than normal)
  • Bark splitting
  • Serpentine galleries (larval galleries generally S-shaped)
  • D-Shaped exit holes

Canopy dieback.

Epicormic shoots.

Bark splitting.

Serpentine galleries.

D-shaped exit hole.

 (Kelly Estes)

Kelly Estes

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