Japanese Beetle Problem? - Ask Extension
Hello! I have 3 year old Eastern Larch trees that seem to be doing well with the exception of one. I noticed that it is drooping, so I've ramped up t...
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Japanese Beetle Problem? #879433
Asked July 30, 2024, 1:44 PM EDT
Hello! I have 3 year old Eastern Larch trees that seem to be doing well with the exception of one. I noticed that it is drooping, so I've ramped up the watering as I read that tamaracks need a lot of water. However, I also notices some brown branches and bugs (Japanese beetles?) as well. I cut off one of the branches and see that it is still green around the inside edges. I've attached some pictures and would appreciate your insight as to what is causing the tree to struggle. Thank you very much!
Hennepin County Minnesota
Expert Response
The insect in your photo is a Japanese beetle. I am unable to find evidence that confirms or denys that they eat larch. If you are seeing them on the tree, in areas that are brown, it is likely caused by the beetles. The least invasive method of control is to drop the beetles in a bucket of soapy water. They are least active in early AM and later afternoon. Here is a link to information about Japanese beetles and control of them.
https://extension.umn.edu/yard-and-garden-insects/japanese-beetles
It is a likely your larch trees are impacted by the previous years of drought. With our lack of rain in the past few years you would have needed to be watering 1"/week when we were not receiving rain. If the damage is caused by the drought this year's rainfall, combined with supplemental watering, will support it's health.
I am also including a link, below, with information about disease/insects that can impact larch trees. At first glance I do not see photos that directly match the one you sent. You have closer access to look over the full tree for symptoms and insects to compare to the explanations and photos.
https://apps.extension.umn.edu/garden/diagnose/plant/evergreen/larch/yellowedneedles.html
https://extension.umn.edu/yard-and-garden-insects/japanese-beetles
It is a likely your larch trees are impacted by the previous years of drought. With our lack of rain in the past few years you would have needed to be watering 1"/week when we were not receiving rain. If the damage is caused by the drought this year's rainfall, combined with supplemental watering, will support it's health.
I am also including a link, below, with information about disease/insects that can impact larch trees. At first glance I do not see photos that directly match the one you sent. You have closer access to look over the full tree for symptoms and insects to compare to the explanations and photos.
https://apps.extension.umn.edu/garden/diagnose/plant/evergreen/larch/yellowedneedles.html
