Hi Becky, 

Here is a link to our website which discusses Elm Leaf Beetle. Make sure that the damage/insects you are  seeing on your Elm trees is indeed  Elm Leaf Beetle. If any concerns, take photos or bring in sample (leaf and insect if possible) to our office (address below). 

Here is a link to our website which discussed Elm Leaf Beetle. There is a link to management as well (on page 7) which does note systemic insecticides.  

https://extension.oregonstate.edu/gallery/common-insects-cause-plant-damage-central-oregon

Here is additional information: 

https://ipm.ucanr.edu/PMG/PESTNOTES/pn7403.html
 Note that "healthy elm trees can tolerate substantial damage to leaves" and that contact insecticides can provide control on smaller trees.

Should you want to reach out to a certified arborist, you can go to https://www.treesaregood.org/

Please reach out if you have further questions.

Lisa

Lisa Cowan

Outreach Program Coordinator – Community Horticulture Program

Oregon State University

OSU Extension Service – Deschutes, Crook, Jefferson Counties

3800 SW Airport Way, Bldg #4

Redmond, OR 97756

Tel.:<personal data hidden> (direct line) I<personal data hidden> (x79590 - main line)

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