White Pine bugs

Asked July 9, 2020, 10:25 PM EDT

Today we noticed that one of our 100' white pine is swiftly dying. It was not dying a couple of days ago. We can hear insects gnawing away at the base of the tree and there is saw dust at the bottom of the tree. The bugs sound a bit like a cricket, but it sounds different. We live in a forest of pines and it concerns us that whatever it is will devastate all our trees. Most all our tree are > 100' tall. There are White Pines and Red Pines. There are white spruces, balsams, and some other kinds of spruce trees. I even have one Siberian Spruce I bought many years ago at an MUS plant sale. It is about 20' tall now. Can you help us identify what is killing this tree and if I should have it taken down quickly? Is there something that can kill the insect that is killing the tree? We live in southern Cheboygan County about a mile from Otsego County line. We are in Nunda township on the north edge of the Pigeon River State Forest. https://www.google.com/maps/search/Nunda+twsp,+mi+49799-9412/@45.2213974,-84.5450924,3186m/data=!3m1!1e3 Thank you, Jeff Katke 1860 Ridgeline Drive, Wolverine, MI 49799-9412 Call: (248) 318-6360 Home: (231) 525-9995 Fax: (989) 930-4610 Email: jwkatke@gmail.com

Cheboygan County Michigan

3 Responses

Hello,

The insects you hear are most likely pine sawyer larvae, Monochamus spp. The larvae develop in declining or dead trees. They are considered secondary. White pine decline is difficult to diagnose.

White pine decline is more often caused by cultural and environmental problems than by insects or disease. Heat stress and heavy clay soils are often the cited as the cause.

For more on white pine decline see:​​

https://www.bartlett.com/resources/Cultural-Disorders-of-Eastern-White-Pine.pdf

http://hyg.ipm.illinois.edu/pastpest/200406a.html

https://www.extension.purdue.edu/extmedia/BP/BP-34-W.pdf

Howard

Thank you for the prompt response. One question, Do I need to take the tree down soon and bury it to kill the bugs and keep the other trees healthy?


Hello again,

I would take the tree down for safety reasons if it is dead. As I said, the sawyer beetles are secondary, they only attack declining or dead trees, they don't bother healthy trees so there isn't a need to bury the wood from the dead tree.

Howard