Top Left: Eastern Ash Borer Gallery Exposed
Bottom Left: Eastern Ash Borer on tip of index finger
Right: Eastern Ash Borer
Ash is not only attacked by emerald ash borer. On my trip to Boulder, Colorado, bark peels of ash branches uncovered galleries and adults of Eastern Ash Borer, Hylesinus aculeatus, in addition to Emerald Ash Borer. The Eastern Ash Borer is a scolytid bark beetle and is much smaller than Emerald Ash Borer, a Buprestid. The Eastern Ash Borer primarily attacks stressed, weakened or felled trees. The larval galleries of Eastern Ash Borer extend symmetrically from a center egg gallery. Unlike the D-shaped exit holes of Emerald Ash Borer, Eastern Ash Borer typically leaves clusters of round holes. Larvae cause imperfections in the wood but are seldom of economic importance. They do not kill healthy trees, but can hasten the death of stressed trees including trees damaged by Emerald Ash Borer.
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