Published: June 21, 2009 11:58 pm      

DEC: Tangling with new invasive species

Asian beetle has potentially devastating taste for ash trees

Another invasive species has arrived in Western New York, and state officials are taking up arms to eradicate the creatures.

Although it doesn’t pose a threat to humans, the emerald ash borer, a type of beetle native to Asia, has the potential to wipe out the ash tree population — on a grander scale than what Dutch elm disease did to urban landscapes in the 1960s and ’70s.

It would also, state officials say, have an impact on the state and national economies. The eastern U.S. produces $25 million in ash timber a year. When you factor in other businesses that benefit from ash wood, the economic losses nationwide could be more than $20 billion.

Officials say it was only a matter of time before the insect arrived in New York state.

“It is not surprising,” said state Agriculture Commissioner Patrick Hooker. “This beetle has been detected on either side of Lake Ontario for several years now and there is little that can be done to stop the natural spread of this devastating pest.”

Since its 2002 detection in the U.S., the beetle has migrated from where it was first found — the Detroit area — to 13 states and at least two Canadian provinces.

Awkward in flight, the emerald ash borer mostly migrates by “artificial” means, such as movement of infested firewood, logs and nursery stock.

In an effort to halt or at least slow down its spread, the New York state Department of Environmental Conservation last year banned transporting firewood more than 50 miles. That ban is not expected to be lifted any time soon.

“We’re hopeful to stop the spread of firewood,” said Wayne Cooper, a regional forester for the DEC. “People should burn it at home, and don’t bring it into state parks.”

The first appearance of the beetle in New York state was confirmed this week, in the Cattaraugus County Town of Randolph, where between 20-30 trees have been affected.





The emerald ash borer

Approximately 1/2-inch in length, with shiny green wings and a copper-colored underside, the adult emerald ash borer can be found munching on the leaves of ash trees.

The beetle itself doesn’t do much damage to the trees. The danger lies with the larva. After a beetle lays its eggs on the tree’s bark, the larvae burrow underneath, creating tunnels called “galleries.” Moving in serpentine fashion, the larvae galleries go beyond the cambium layer, which controls growth, into the phloem, disrupting water and nutrient transport.

“The outside of the tree looks fine,” said Wayne Cooper, a regional forester for the DEC, “but inside it is getting strangled.”

Back on the surface, the adult beetle leaves behind a D-shaped hole that is difficult to notice at first.

Signs that a tree is infected by the beetle include the canopy dying off; a yellowing, extensive sprouting from the roots and trunk; and browning of leaves. Infested trees may also exhibit woodpecker damage.

“Woodpeckers are better at finding these insects than we are,” Cooper said.