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Please tell me the nam... #649577

Asked June 11, 2020, 4:18 PM EDT

Please tell me the name of this disease on my butterfly bush and how to cure it. These are no signs of bugs, or mold on the fronts or backs of the leaves. The leaf slowly develops tiny brown dots, that appears to be from loss of something IN the leaf (chlorophyll?) rather than something on top of the leaf (like a bug). Please advise me as to how to solve this. I am losing the whole bush to this. Thank you very much for you assistance. I submitted this question and the reply was that it had already been aanswered in question 649558. it did not say HOW to get to question 649558 and I am unsuccessful in searching for it.  Again, please help.  Thank you very much.

Martha Buchanan, Royal Oak, Michigan


649558

Oakland County Michigan

Expert Response

This appears to be damage from a sucking insect such spider mites which are common on butterfly bushes.  Take a close look and see if you can find any webbing on the underside of the leaves. Place a sheet of paper under a branch and then shake the branch to see if any mites fall onto the paper. During the growing season, you can spray horticultural oil and/or insecticidal soap. Below is a link to a web site that provides more detail about seasonal treatments and products.  
Monitor your shrub after application and re-apply as needed. Since mites and other insects tend to feed on plants that are stressed, make sure to keep your shrub watered during dry periods.
https://extension.entm.purdue.edu/publications/E-42/E-42.html

Hope that helps!


Diane - MSU Advanced Extension Master Gardener Replied June 16, 2020, 10:13 AM EDT

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