Emerald Ash Borer confirmed in Decorah

The emerald ash borer has been discovered in Decorah.

That's the word from the Iowa Department of Agriculture, which says a consulting arborist was drawn to the tree in Decorah after noticing evidence of EAB damage.  Further investigation revealed distinctive S-shaped galleries and an EAB larva (immature beetle) underneath the bark of the infested tree.  The collected larva was sent to the USDA Systematic Entomology Laboratory, where it was confirmed positive for EAB.

"We are fortunate that others are aiding in the effort and alerting us of trees that are suspect for emerald ash borer, especially in areas not yet known to be infested," said Iowa Department of Agriculture and Land Stewardship EAB and gypsy moth coordinator Mike Kintner.  "Like other states, we will continue to track this pest as it expands to new areas."

The adult emerald ash borer is an elusive metallic-green beetle measuring approximately ½ inch long, making it challenging to detect in the landscape. The adult females lay eggs in the bark crevices of ash trees where they hatch, boring into the inner bark. During this immature stage the progression of larvae feeding and development disrupts the trees' ability to transport water and nutrients. EAB infested ash trees include thinning or dying branches in the upper canopy, evidence of woodpecker activity, S-shaped feeding galleries under dead or splitting bark, D-shaped exit holes and water sprouts (along the trunk and main branches).  

Federal quarantines are in place to restrict the movement of hardwood firewood, ash logs, wood chips and ash tree nursery stock out of Iowa into non-quarantined areas of other states. The Iowa EAB Team urges Iowans to use locally sourced firewood, burning it in the same county where it was purchased. Firewood is not only a means of transportation for EAB, but other tree-killing pests as well.

At this calendar date, the window for all preventive treatments remains closed. If a landowner is interested in protecting a valuable and healthy ash tree within 15 miles of a known infestation, he or she should have landscape and tree service companies bid on work, review the bids and treat beginning spring 2016 (early April to mid-May).