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Entomology (Study of Bugs)/Ironwood Tree bug infection question


Linear Bore
Linear Bore  
Linear Bore from far away
Linear Bore from far a  
QUESTION: I have been searching the web trying to find what is causing the enormous ammount of small circular holes that wrap around the  Ironwood tree in rings and go all the way up the tree. I havent seen any insects besides for what appears to be ants. We had noticed it this year in the spring when the snow left, the tree was sagging diagonally which is what caught our eye at first then we saw circles which when we looked closer was what appeared to be holes bored from a bug of some kind. I was wondering if there is anything that can be done besides cut it down, will it spread to other trees and if so is there any way of preventing the spread of the insects causing this? If there is any other information that might help it would be very much appreciated. Thank you for taking the time and look forward to your reply.


Pretty certain the damage is being done by a sapsucker, a type of woodpecker, rather than insects.  The images you included depict the classic pattern generated by these birds.


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QUESTION: Is there anything that can be done to stop the woodpecker(s) from doing this or anything i can do for the ironwood tree? It's starting to hang more and more slanted as time goes on. i live up in upper peninsula Michigan about 10 miles out of town and there are alot of birds and insect life around. Do you think it could be multiple woodpeckers or do they have the capabilities of boring the tree by themselves to this degree? And if we are able to do something about the bird and/or tree would another bird just move in and start the cycle all over again?? Another thing i have a question is should the tree be taken down? It has green growth, however it looks to be slowly dying far at the top. I really appreciate your professionalism and your intelligence with this situation. Thank you very much for what you have said and done for me so far, if it wasnt for you id still be thinking this was an insect problem so i really appreciate you steering me in the right direction. Thank you


I cannot be of further help, except to say it is likely one bird as they are pretty territorial.

I suggest you consult an arborist about the tree itself.  I know nothing of plants and trees myself.  You may have an urban forestry department in your city and they might be able to help you for free.  That said, trees do not live forever.  Healthy trees can take a beating, though, so I also wouldn't panic.

Best wishes for a successful resolution to this.  Thank you also for the compliments.



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Eric R. Eaton


I answer insect and spider identification questions ONLY. Attach images if possible. No "what bit me?", "what do I feed this bug in captivity?", or science fair project questions please. NO TECHNICAL QUESTIONS ABOUT INSECT PHYSIOLOGY.


Principal author, Kaufman Field Guide to Insects of North America. Professional entomologist employed previously at University of Massachusetts, Chase Studio, Inc., and Cincinnati Zoo; contract work for West Virginia Department of Natural Resources, Smithsonian Institution, and Portland (Oregon) State University.

Author, Kaufman Field Guide to Insects of North America, Missouri Conservationist magazine, Ranger Rick, Birds & Blooms, Timeline (journal of the Ohio Historical Society). I have contributed to several books as well.

Oregon State University, undergraduate major in entomology, did not receive degree.

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One of the top 50 experts in all categories for, 2009.

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Principal author of the Kaufman Field Guide to Insects of North America, Smithsonian Institution (contract), Cincinnati Zoo (employer), Portland State University (contract), Chase Studio, Inc (employer), Arkansas Museum of Discovery (guest speaker). Currently seeking speaking engagements, leadership roles at nature festivals, workshops, and ecotours.

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