I have been told by a tree care company that my ash trees are infected with bores. They can be treated, and the trees should survive. Though my internet research I found ample information on emerald ash bore, however, that the research was largely on trees in Michigan. Would I have emerald ash bores, or do another type of bore exist in Utah? The tree care company suggested treatment in the spring, and another in the summer. Does that sound appropriate?



First I would ask if the tree care company and individuals you had look at your trees were certified arborists through the International Society of Arboriculture (ISA).  Here is a listing (not complete) of certified arborist for hire in Utah click on http://www.utahurbanforest.org/certified.html and for ISA information go to http://www.isa-arbor.com/certification/certification.aspx .

Emerald Ash Borer is currently a problem in Michigan, but we have other types of borers in Utah that do affect ash.  Here is a link to USU fact sheet on Lilac/Ash borer which is a clear winged moth that has not been updated recently, so the chemicals allowed may not be available http://extension.usu.edu/files/publications/factsheet/ash-lilac-borers93.pdf

A more current factsheet and with pictures regarding tree and shrubs borers is from Colorado State Extension - go to http://www.ext.colostate.edu/pubs/insect/05530.pdf and you'll notice there are a lot or borers but treatments are not always effective - must have proper identification of pest to choose the best management.

If your ash is in good shape and not had a lot of dieback and is has good roots with lots of room for the roots - ashes are big trees and need adequate roots for absorbing water and nutrients and support of a large canopy (not impacted by sidewalks, decks or house foundation) the tree may possibly be worth treating - but make sure they have diagnosed the pest appropriately.

Posted on 27 Mar 2009

Maggie Shao
Horticulture Agent, Salt Lake County

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