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September 25, 2012

EAB likely in most Lafayette-area trees, Purdue expert says

adult emerald ash borer

An adult emerald ash borer feeds off a leaf. (Purdue University Department of Entomology photo/John Obermeyer)
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WEST LAFAYETTE, Ind. - The highly destructive emerald ash borer has been discovered in the city after being found in neighboring Lafayette last year, suggesting that most ash trees in the area now are infested, a Purdue University entomologist and expert on the invasive beetle said.

Cliff Sadof said homeowners need to decide now if they want to protect their trees next spring because it is time to plan against next year's crop of beetles or begin putting money aside to pay for tree removal. He predicts that the beetle will kill every untreated ash in the Lafayette-West Lafayette area in 4-5 years.

"To keep ash trees alive, they will have to be protected with an aggressive insecticide program for the next six years as the tidal wave of beetles rolls through our community," Sadof said. "After that time, you can reduce insecticide use because most of the EAB will either have starved to death or have been killed by an insecticide-treated tree."

The discovery of the beetle in a nearly dead ash tree bordering Sagamore Parkway was confirmed last week. The insect was first found in Tippecanoe County near Americus in 2010 and was confirmed in Lafayette in June 2011.

West Lafayette city forester Bev Shaw said the city has been anticipating the arrival of the EAB since 2003 and has been planting resistant trees along city streets since then. "We are planting a variety of tree species to protect against pest outbreaks in the future," she said.

Presence of the insect is a death sentence for all ash trees except those protected with certain insecticides.

"The bug will kill trees slowly at first," Sadof said. "But the number it kills doubles every year."

Symptoms of infestation include loss of leaves in the upper one-third of the tree's canopy, vertical splits in the bark, D-shaped exit holes on the trunk, S-shaped tunnels under the bark, heavy woodpecker activity, and shoots coming out of the trunk.

Neighborhoods with ash trees are encouraged to save money by coordinating group contracts for tree care services. Visit Purdue's EAB page at http://www.eabindiana.info for more detailed information on how to organize a neighborhood and protect trees.

The EAB has been found throughout Indiana except for 13 counties in the southwest corner of the state. It is illegal to move firewood or any ash tree parts from quarantined counties into the protected area. An interactive map of Indiana's quarantined counties is available at http://www.in.gov/dnr/entomolo/5349.htm. Indiana also is included in a regional federal quarantine for the EAB. 

New infestations of the insect have been found in Connecticut, Kansas and Massachusetts over the summer, bringing the number of infested states to 18. 

Writer: Keith Robinson, 765-494-2722, robins89@purdue.edu

Sources: Cliff Sadof, 765-494-5983, csadof@purdue.edu

Bev Shaw, 765-775-5161, bshaw@westlafayette.in.gov

Annemarie M. Nagle, Purdue University forest pest outreach coordinator, 765-494-0822, naglea@purdue.edu

Related website:
Purdue University Department of Entomology

Ag Communications: (765) 494-2722;
Keith Robinson, robins89@purdue.edu
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