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Pieris japonica, sooty mold infestation #241360

Asked May 03, 2015, 6:05 PM EDT

Is there a an insecticide that will remove sooty mold from Pieris japonica? I have three bushes that were infested last year and four more that may have been infested this year. So far I have tried to wash off the scale with a strong water spray earlier this week and I think I should be doing more. Also the three bushes affected last year don't appear to be in good shape. Can this sooty mold kill the plant? I live in south Salem.

Marion County Oregon

Expert Response

Hi : The fundamental problem is the scale you have observed, which is almost certainly azalea bark scale. This scale, as with others, exudes honeydew as it feeds which is deposited on twigs and leaves. Sooty mold grows on this honeydew. So eliminating the scale is the way to solve the problem. Below you will find website addresses for information on azalea bark scale as well as information on scale control from the PNW Insect Management Handbook. Please contact me directly with further questions at the email address below-Thanks!

http://insect.pnwhandbooks.org/hort/landscape/hosts-and-pests/azalea-rhododendron-azalea-bark-scale

http://insect.pnwhandbooks.org/hort/landscape/common/landscape-pests-scale-insect


Neil Bell Replied May 05, 2015, 8:16 AM EDT

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