Invasive Emerald Ash Borer Lays Waste to 17-Mile Hiking Trail Prompting Closure for Pennsylvania's Tyler Arboretum

As invasive ash emerald borers expand and destroy trees, Pennsylvania's Tyler Arboretum is closing its 17-mile hiking trail.

Tyler Arboretum Hiking Trail Closure

Visitors to Delaware County's 650-acre Tyler Arboretum will soon witness vibrant fall foliage on dogwoods, ginkgoes, and maples.

Regrettably, 17 miles of trails outside the arboretum are closed due to the invasive emerald ash borer's devastating impact.

A contractor is working to remove 900 ash trees, which are casualties of this pest that began its destructive journey through Pennsylvania's forests in 2007.

Although the arboretum remains open with events, the invasive pest has finally reached Delaware County, concluding its destructive rampage that began in 2012 in the Philadelphia area.

Some of Tyler Arboretum's victims were over a century old.

Invasive Emerald Ash Borer

The emerald ash borer (EAB) is a wood-boring insect that is invasive and native to areas of Asia.

It was discovered in 2002 in the Detroit, Michigan, and Windsor, Ontario, regions, but it has probably been present in North America undiscovered since the 1990s.

According to experts, wooden shipping containers or packaging materials may have been used to smuggle the EAB into Detroit.

Since its introduction, the EAB has spread quickly across North America, having a devastating impact on the ash tree population and killing up to 99% of ash trees in its path.

Throughout all regions of North America with ash trees, there is a possibility of an established EAB colony.

Nearly 900 Trees in Danger

Last spring, Arboretum officials underestimated the damage caused by the emerald ash borer in Middletown Township.

An updated GIS survey revealed nearly 900 hazardous ash trees near trails, posing safety risks to the public.

Some, are over 120 years old, and others are 30 to 50 years old.

To address this, an ecological working group was formed. Phase one involves contractor Cox & Co. removing 584 trees to reopen 9.5 miles of trails. Progress is slow due to tree locations. This removal will transform the forest's appearance and is costly.

The arboretum seeks donations to support the removal efforts.

Cost of Damages

Skuja anticipates the first phase will cost over $500,000, with uncertain expenses for subsequent phases depending on various factors.

The arboretum plans to create new habitats and aims to raise $1 million to $2 million for comprehensive landscape restoration. This challenge presents an opportunity for long-term regeneration.

Erin Mooney, executive director of the Schuylkill Center for Environmental Education, noted a similar emerald ash borer issue on their 365-acre property, though not as severe as Tyler's infestation.

They sympathize with Tyler's situation, having witnessed the problem for five years at their own center.

18 Years of Infestation and Eradication Plans

Pennsylvania's DCNR initiated a plan in 2014 to combat the emerald ash borer infestation, which had already reduced the state's ash trees by 12%.

The worst of the 18-year infestation seems to be over, as the pest has mostly wiped out untreated ash trees, formerly 4% of the state's forests.

Delaware County saw the infestation about six years ago, leading to numerous dead ash trees at Tyler Arboretum.

Widespread treatment is impractical and costly. The remaining hope lies in "lingering ash" trees that may be genetically resistant, though more research is needed before recommending ash tree planting.