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15 year old cluster of Vine Maples infested with borers. Risk management for other trees? #489482

Asked October 09, 2018, 10:21 PM EDT

Assuming we have to remove our infested cluster of Vine Maples, should we not plant new Acer species? Is there danger to be managed for our close-by Lilac or our backyard Rhodies, Yew, Henry Lauder (curly) Filbrt, and Japanese Maple? (No evidence of infestation.) Our neighbors have a large old oak and several conifers. Are they endangered? Are annual chemicals a needed precaution? Which kind of borer does ours appear to be? It bores very deep into the wood; not just under the bark. I discovered it as I made some walking canes from prunings. Should I dispose of all the infested trees including the roots? Might any new shoots be treated and grown? Any advice is welcome.

Marion County Oregon

Expert Response

Wood borer infestations such as yours are not usually the primary cause of the problem - they are just taking advantage of a tree that is declining for other reasons.From the photo is appears that the tree had a stem canker disease or physical damage that exposed and weakened the trunk, which made an attractive site for wood borers to attack. Stem canker diseases are a common problem with maples so it is important to know if there was physical damage or stem canker disease in your maple. If it was a stem canker, you might want to examine your other maples for signs of this problem and look into remedies for this.

While a definitive diagnosis requires identification of the specific wood boring insect, wood borers are likely not a major threat to healthy, undamaged vine maples nearby. The borer in your case appears to be a round headed borer (of which there are many different species, hard to identify from larvae alone, an adult borer beetle specimen would be needed). Stressed or declining parts of trees are going to be colonized by insects. Round headed wood borers in dead wood are not usually a threat to healthy live trees.



An Ask Extension Expert Replied October 14, 2018, 3:43 PM EDT

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