Chestnut Tree Leaves Being Eaten

Question: Hello

 I have  2 Colossal Chestnut (Castanea sativa x crenata), 2 - Precoce Migoule Chestnut (Castanea sativa x crenata), and 4 - Chinese Chestnut (Castanea mollissima). The leaves of the Colossal trees look like they are being eaten by some type of insect. The leaves on the other trees look fine. Do you have any thoughts on what is eating the leaves and how would I control it? Both of these trees look like they will blossom for the first time this year. Whatever is eating these leaves looks similar to what eats the leaves of one of our rose bushes. Any insight you may have is greatly appreciated.

responder: An Ask Extension Expert Replied June 23, 2023, 3:12 PM EDT
response: Hello,  Based on what I see in your single image, compared to many perennial cropping systems in Michigan, chestnuts have relatively few pests of minor importance. Most commonly, growers manage against potato leafhopper, Japanese beetle, rose chafer, and potentially European red mites. Additionally, growers should be scouting for the potential invasive pest, the Asian chestnut gall wasp.  Because those leaves look similar to what eats the leaves of one of your rose bushes. I believe the problem is Japanese beetle and/or Rose chafer - See the section on Japanese beetle and Rose chafer at this link:  https://www.canr.msu.edu/chestnuts/pest_management/insects#:~:text=Compared%20to%20many%20perennial%20cropping%20systems%20in%20Michigan%2C,the%20potential%20invasive%20pest%2C%20Asian%20chestnut%20gall%20wasp.  Please get a confirmed diagnosis from the MSU Diagnostic Plant & Pest Lab - Please email your digital images prior to bringing or sending physical samples. Images can be sent to <personal data hidden>.   PLEASE SEND AN ADDITIONAL CLEAR AND CLOSE IMAGE OF FOUR LEAVES - TWO THAT SHOW THE FRONT SIDE AND TWO THAT SHOW THE UNDER-SIDE (FLATTEN OUT)  MAKE SURE THESE IMAGES SHOW EVIDENCE THAT THE LEAVES HAVE BEEN EATEN. IF YOU SEE THE INSECT, TAKE A CLEAR CLOSE-UP IMAGE OF THAT, TOO - THANK YOU!!  MAKE SURE IN THAT E-MAIL YOU INCLUDE YOUR NAME, ADDRESS, AND PHONE NUMBER!!   Be prepared. The lab may ask for more images - THE LAB WILL LET YOU KNOW IF A SAMPLE NEEDS TO BE SENT - There is a $20-25 dollar fee (if they need a sample sent).   Lab email: <personal data hidden>  Lab phone:<personal data hidden>  Hours of operation: Monday through Friday, from 8:00 AM to 5:00 PM.   PLEASE READ BELOW ON PREPARING YOUR SAMPLE (if the lab needs a sample)   From the lab: Please do not ship samples on Fridays. Due to the current COVID-19 circumstances, please allow additional processing time. They thank you for your patience and understanding.   Every sample must be accompanied by a completed submission form. Please place the form in a separate resealable bag to prevent it from getting damp or soiled. The form is at this link: https://www.canr.msu.edu/pestid/uploads/files/General_Sample_Submission_Form_May2022.pdf.   Complete details of submitting a sample are at this link: https://www.canr.msu.edu/pestid/submit-samples/   I hope this helps!

responder: The Question Asker Replied June 26, 2023, 1:43 PM EDT
response: Hello, Thank you for responding to my inquiry.  I apologize for only sending a picture of a single leaf.  I will try to send a couple of better pictures.  In the meantime I view the first link that you provided and I think rose chafers are what is eating the leaves on the 2 colossal trees.  They are pretty good, maybe 7 years old and they do not have as many leaves as I thought there should be. (Not that I'm a chestnut tree guru).  What should I do to eliminate them?Interestingly enough I was looking at the leaves of a pin oak in our front yard because something is eating its leaves.  I was examining one leaf and I noticed a light green speck on it.  Upon closer examination it was some kind of insect.  It was very similar to the ones shown in the link for a potato leafhopper.  This tree is 20 years old and probably 50% or more of the leaves show some level of damage.  I'm not sure how one goes about eradicating these pests, but I imagine it's pretty costly.At this point do I need to do what you have typed in red in your reply?  With respect to the chestnut trees, I'm pretty confident the damage to the leaves is from the rose chafers.  I just need to know how to get rid of them and how to keep them away.  For the pin oak I don't think there is much I can do with.Thank you again for getting back to me.ScottOn Fri, Jun 23, 2023 at 3:12 PM Ask Extension <<personal data hidden>> wrote:

responder: An Ask Extension Expert Replied June 26, 2023, 3:00 PM EDT
response: Hello Again,  Click on this link: https://www.canr.msu.edu/resources/michigan-chestnut-management-guide Download the 2023 Michigan Chestnut Management Guide Look at the tables on Pages 8 through 12 in the - Insect Management Section of this guide  The information presented here does not supersede the label directions. The efficacies of products listed have not been evaluated on chestnuts in Michigan. This information is for educational purposes only. Reference to commercial products or trade names does not imply endorsement by MSU Extension or bias against those not mentioned. To protect yourself, others, and the environment, always read the label before applying any pesticide. Although efforts have been made to check the accuracy of information presented, it is the responsibility of the person using this information to verify that it is correct by reading the corresponding pesticide label in its entirety before using the product. Labels can and do change.  For additional chestnut management information, visit: https://www.canr.msu.edu/chestnuts/pest_management/insects See the Rose chafer section  I hope this helps!

responder: The Question Asker Replied June 27, 2023, 8:42 AM EDT
response: Hello, Thank you for sending the 2 links regarding chestnut management.  They are very informative and will be very useful in the future should I have any questions regarding chestnut tree management of my 8 chestnut trees.ScottOn Mon, Jun 26, 2023 at 3:00 PM Ask Extension <<personal data hidden>> wrote:

responder: An Ask Extension Expert Replied June 27, 2023, 9:59 AM EDT
response: You are welcome! Have a great day!