In which part of the tree litter does its hunteri hide? - Ask Extension
I want to help my ips-infected blue spruce, but I don't know which part of the litter under the tree I need to remove.
There are dirt, needles, smal...
Knowledgebase
In which part of the tree litter does its hunteri hide? #924248
Asked February 04, 2026, 11:41 PM EST
I want to help my ips-infected blue spruce, but I don't know which part of the litter under the tree I need to remove.
There are dirt, needles, small twigs and larger branches under the tree. The tree is 40 feet tall, so there is a large area to clean up.
Is it just the twigs and branches? Do I need to remove pine needles? What about soil? I don't understand where the beetles hide in winter.
Boulder County Colorado
Expert Response
Hello Melody,
Thank you for writing to CSU Extension with your question about ips beetles. They develop under the bark and produce girdling tunnels that can cause dieback and kill trees.
Has someone confirmed that you do have an ips beetle infestation? Assuming that you have, I'm sending a link to a CSU Extension publication titled "Ips Beetles", as well as a publication from the Colorado State Forest Service (this one isn't as extensive as the CSU Extension publication but still contains valuable information. In it, there are links to other materials that may be useful.
In them you'll find information about symptoms, life cycle and management. Adults overwinter under the bark of the tree or in surrounding litter at the tree base, primarily freshly cut material that results from pruning or thinning.
Chemicals only work as a preventive measure. Once a tree is infested chemical treatments will not help the tree.
https://csfs.colostate.edu/forest-management/common-forest-insects-diseases/ips-beetle/
https://extension.colostate.edu/resource/ips-beetles/
I hope this information is helpful to you. If you have additional questions, feel free to contact us again.
Regards,
Colorado Master Gardener
CSU Extension Boulder County
Thank you for writing to CSU Extension with your question about ips beetles. They develop under the bark and produce girdling tunnels that can cause dieback and kill trees.
Has someone confirmed that you do have an ips beetle infestation? Assuming that you have, I'm sending a link to a CSU Extension publication titled "Ips Beetles", as well as a publication from the Colorado State Forest Service (this one isn't as extensive as the CSU Extension publication but still contains valuable information. In it, there are links to other materials that may be useful.
In them you'll find information about symptoms, life cycle and management. Adults overwinter under the bark of the tree or in surrounding litter at the tree base, primarily freshly cut material that results from pruning or thinning.
Chemicals only work as a preventive measure. Once a tree is infested chemical treatments will not help the tree.
https://csfs.colostate.edu/forest-management/common-forest-insects-diseases/ips-beetle/
https://extension.colostate.edu/resource/ips-beetles/
I hope this information is helpful to you. If you have additional questions, feel free to contact us again.
Regards,
Colorado Master Gardener
CSU Extension Boulder County
Hi,
Sent from Proton Mail for iOS.
-------- Original Message --------
On Thursday, 02/05/26 at 20:55 Ask Extension <<personal data hidden>> wrote:
Thanks for responding.
Yes, I have confirmed ips beetles.
I have read these publications but I do not know specifically what litter means.
Is it twigs and branches under the tree, or does it include needles and dirt?
I want to know where in the litter the beetles are overwintering.
Thank you,
Melody
Sent from Proton Mail for iOS.
-------- Original Message --------
On Thursday, 02/05/26 at 20:55 Ask Extension <<personal data hidden>> wrote:
Hi Melody,
Thank you for getting back to me confirming Ips beetles. The beetles, primarily the larvae, but sometimes adults as well, overwinter under the bark of the trees. When the adults emerge in the spring, they begin "looking" for stressed trees, freshly cut green logs or firewood, or any green branches under the tree.
They don't overwinter in the soil or in pine needles. You should remove the twigs and branches.
I hope this information is helpful to you. Please reach out to us again if you have more questions.
Regards,
Colorado Master Gardeners
CSU Extension Boulder County
Thank you for getting back to me confirming Ips beetles. The beetles, primarily the larvae, but sometimes adults as well, overwinter under the bark of the trees. When the adults emerge in the spring, they begin "looking" for stressed trees, freshly cut green logs or firewood, or any green branches under the tree.
They don't overwinter in the soil or in pine needles. You should remove the twigs and branches.
I hope this information is helpful to you. Please reach out to us again if you have more questions.
Regards,
Colorado Master Gardeners
CSU Extension Boulder County
Thanks,
Perfect information that I can action.
I appreciate this service from experts.
One last question from experts if you have time. We haven't had much snow this winter and it is so warm right now. About how much water would a forty-foot tree need to help it get through this dry spell?
I want to do all that I can to help it be strong enough to get through its beetle infestation.
Thanks,
Melody in Longmont
On Friday, February 6th, 2026 at 11:32 PM, Ask Extension wrote:
Hi Melody,
Thank you for reaching out to us regarding your 40 foot tree.
The watering suggestion is 10 gallons per an inch of tree diameter. Since Blue Spruce are native to the higher elevation and in moist habitat, it might be good to increase that to 11 gallons per an inch of diameter.
Water the entire area underneath the tree branches, the area near the canopy of the tree (outer branches) are the most important as that is where many of the fine watering roots of the tree are.
During the Fall and Winter months it is recommended if your tree did not receive an inch of rain or 12 inches of snow for 30 days, then you need to water your tree.
Here is an article on Winter Watering.
https://extension.colostate.edu/resource/fall-and-winter-watering-of-plants-and-trees/
Hope that helps, and please let us know if you have any other questions.
Boulder County Master Gardener
Thank you for reaching out to us regarding your 40 foot tree.
The watering suggestion is 10 gallons per an inch of tree diameter. Since Blue Spruce are native to the higher elevation and in moist habitat, it might be good to increase that to 11 gallons per an inch of diameter.
Water the entire area underneath the tree branches, the area near the canopy of the tree (outer branches) are the most important as that is where many of the fine watering roots of the tree are.
During the Fall and Winter months it is recommended if your tree did not receive an inch of rain or 12 inches of snow for 30 days, then you need to water your tree.
Here is an article on Winter Watering.
https://extension.colostate.edu/resource/fall-and-winter-watering-of-plants-and-trees/
Hope that helps, and please let us know if you have any other questions.
Boulder County Master Gardener
