Trees infested with emerald ash borer

The financial impact of EAB is incredible. Direct costs include tree removals (don’t forget stump grinding) and planting replacement trees. For those people who want to save specific ash trees, stem injections with the chemical ‘emamectin benzoate’ have been extremely effective – but they’re definitely not free. Indirect costs are also large – losing a prime shade tree can result in an increase in electric bills by more than 25%. That loss of shade has also resulted in an increase in water bills, as exposed lawns have needed additional irrigation. Property values have decreased in some communities as the overall tree cover has declined. One study even found an increase in heart and respiratory diseases in those areas that have been hardest-hit by EAB.

Many North Dakota communities’ urban forests are comprised of more than 50% ash trees. In one study of four North Dakota small towns, the cost of removal-and-replacement was estimated from $22,000 to more than $163,000; that study was completed 5 years ago and costs increase every year. Insecticide injections provide an alternative to removals-and-replacements, and may be a cost-effective option for managing the urban forest. The EAB Cost Calculator from Purdue University allows users to compare the costs of different management alternatives: http://int.entm.purdue.edu/ext/treecomputer/.

Technical and financial assistance for developing community-level management plans is available from the ND Forest Service. Contact Gerri Makay at 701-652-2951 or gerri.makay@ndsu.edu for more information. 

Additional information about EAB is available from the ND Department of Agriculture at: https://www.nd.gov/ndda/plant-industries/pest-survey-and-outreach/emerald-ash-borer-eab.  For more information about tree pests such as Dutch elm disease, gypsy moth, and others, please visit the ND Invasives website at: http://www.ndinvasives.org/.