Knowledgebase

Scale covering the branches of a lilac #866536

Asked April 30, 2024, 7:15 PM EDT

I'm trying to figure out what is covering the branches of our lilac bush. Our other one in a different part of the yard doesn't have this issue. I'm wondering if it is a concern, and if might spread to a nearby mountain ash. Thanks.

Ramsey County Minnesota

Expert Response

It is oystershell scale, a common insect. Scale is easiest to treat when they are young. As they mature, they develop a hard outer shell that makes treatment more difficult. I use insecticidal soap. See the following for treatment options: https://extension.umn.edu/yard-and-garden-insects/scale-insects
https://lancaster.unl.edu/oystershell-scale
https://www.canr.msu.edu/resources/oystershell_scale
Terri  Replied May 04, 2024, 12:53 PM EDT

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