Friday, January 28, 2011

Emerald ash borers create woodpecker wonderland

Green ash swamp infested with emerald ash borer (EAB)
Update: EAB continues to ravage ash tree populations in many states. See our more recent post here for details and to find links to treatment options for protecting landscape trees.

Invasive emerald ash borer (EAB) has found an ash bonanza in the impounded swampland east of Delaware Reservoir. The infestation is no surprise for Delaware County, Ohio residents. Complete destruction of ash trees may be inevitable in central Ohio and beyond. Just a few years from now there may be no large ash trees left living.

Optimistic ecologists hope that infestations will not cause complete destruction of large ash trees within natural woodland ecosystems. This area offers a window of insight into this hypothesis. The outcome does not appear promising, here.

Dying green ash twins. Advanced EAB infestation is is killing this green ash tree.
The twin green ash above may not live through this winter. The dozens of scraggly-looking twigs are "epicormic sprouts" indicating that the tree's essential inner bark was disrupted by wood borers a year ago. The sprouts are the trees last defense. Light gray patches indicate woodpecker activity a year ago, fresh yellow exposures are very recent. Woodpeckers don't kill the trees, they respond to fatal EAB infestations wherever destructive larvae are abundant. This tree was infested at least two years ago.

Dozens of green ash trees harbor emerald ash borer larvae in this impounded swamp. Woodpeckers chip away bark to reach the large larvae in heavily infested trees.

These large serpentine galleries are diagnostic for emerald ash borer. Woodpeckers have exposed galleries under the bark of this green ash tree to get to the larvae.

1 comment:

Anonymous said...

Hi Tom,
Would love to be able to use one of your photos in Northern Woodlands magazine. Could you email with you contact information?