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Crepe Myrtle Black Discoloration #858888

Asked February 10, 2024, 2:43 PM EST

This summer we notice a black discoloration to the trunk of the decorative crepe myrtle trees in the front of our home (see photos). This has been a re-occuring annual event however the discoloration is more pronounced this year. What steps should we be taking to protect the trees?

Harris County Texas

Expert Response

Thank you for your question.

Could you send me those images in png format? The HEIC will not open on my computer. 


Thanks!

An Ask Extension Expert Replied February 12, 2024, 2:40 PM EST

HEIC format is the smallest size file. If I use png the files range from 18-22 MB making them too large to send. Compressed files can not be sent on website. Alternative suggestion?

The Question Asker Replied February 12, 2024, 11:03 PM EST

Jpeg format may work also.

An Ask Extension Expert Replied February 13, 2024, 8:43 AM EST

Done

The Question Asker Replied February 14, 2024, 7:58 AM EST

Thank you for those images. 

After consulting with our Horticulture agent she says it looks like Crepe Myrtle Bark Scale. I will attach some publications on this particular pest but once your tree is infected their are limited treatment options. 

You can use soapy water & a soft bristled brush, or a pressure spray nozzle attached to a hose to remove the black sooty mold, loose bark, scales, & egg masses. Their are some insecticidal/pesticide options listed in the two documents but their are potential risks of these products on pollinators. If you do decide to go that direction please follow all instructions on the label for application and to learn the risks associated with use.

https://tfsweb.tamu.edu/uploadedFiles/Crape%20Myrtle%20Bark%20Scale.pdf

https://citybugs.tamu.edu/files/2010/05/EHT-049-Crape-myrtle-bark-scale.pdf

An Ask Extension Expert Replied February 20, 2024, 2:40 PM EST

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