Crape Myrtle fungus?

Question: Brookside Gardens suggested I reach out to you to see if you can identify what's going on with my crape myrtle.  It blotchy white areas and scarring on the trunk. Also how to get rid of it. I've attached pictures.  Thanks.

responder: Answered by the Home and Garden Information Center (HGIC), University of Maryland Extension. For timely gardening information and tips, subscribe to our Maryland Grows blog and quarterly newsletter. Follow us on Facebook, Instagram, and YouTube. Replied March 29, 2023, 11:19 AM EDT
response: These appear to be Crapemyrtle Bark Scale, a relatively new (to our area) insect pest that feeds through the bark on plant sap. Scale insects can be challenging to control, though fortunately even this non-native species is consumed by a few of our local native lady beetles (ladybugs). Since some of the scale visible in your photo appear to be gone or damaged, those natural controls might be at work already in your landscape.  If the scale population is large or causing the plant enough stress to shed leaves prematurely or cause branch dieback, then you may need to resort to using insecticides since the physical removal of enough scale isn't feasible (unless you wanted to replace the plant with another species instead). Options for pesticide management are given in the linked page above (plus the other page it links to for more detail). Given the size of the tree and some of the chemicals involved that might be warranted, we suggest working with a certified pesticide applicator (these individuals are certified by the MD Dept. of Ag.) so they have the proper application equipment, the ability to source certain products, and (hopefully) the experience with this pest to know when during its life cycle certain treatments will have the greatest impact. Scale management often takes more than a year to bring populations down to harmless levels.  Miri

responder: The Question Asker Replied March 29, 2023, 12:50 PM EDT
response: Could using a pressure washer help get rid of them?On Wed, Mar 29, 2023, 11:19 AM Ask Extension <<personal data hidden>> wrote:

responder: Answered by the Home and Garden Information Center (HGIC), University of Maryland Extension. For timely gardening information and tips, subscribe to our Maryland Grows blog and quarterly newsletter. Follow us on Facebook, Instagram, and YouTube. Replied March 29, 2023, 4:09 PM EDT
response: We're not certain, because while a high-pressure spray (high relative to the pressures a garden hose produces) of plain water is often enough to remove many kinds of soft-bodied garden pests (like aphids), the pressures produced by a pressure-washer machine are intense enough that they may remove bark on a thin-barked species like Crapemyrtle. Such an injury could do more serious damage to the tree than the scale would. You can experiment if you have a comparatively lower-pressure machine (electric as opposed to gas-powered, say) and can reach an infested portion of the trunk or major branches that you're willing to sacrifice should the force of the water prove to be too much for the bark. Only a few small fractions of an inch of bark would need to be removed to expose the living tissues underneath that need to stay protected. If you try it and see green tissues exposed after spraying, you've removed too much bark/wood.  If you wanted to try water removal before considering pesticides, the less-risky approach would be to use a normal garden hose water pressure (with a spray nozzle) to help you dislodge scale that you simultaneously rub off the bark with your fingers or with a soft-bristled brush. You need to be able to knock the scale off or squish them while not abrading the bark. The challenge here is that any form of physical removal, while a preferable first step in managing most pest insects, is hard to do well for scale since they glue themselves to the bark, are fairly flush with the wood and pretty flat-bodied, and can occupy very hard-to-access nooks and crannies in the bark and branches, so you won't be able to get them all. Granted, you may get enough to knock the population down for awhile to allow ladybugs and other natural control measures time to keep them suppressed, which is the end goal, but this is harder to do to a sufficient degree manually when trees are this tall.  Miri

responder: The Question Asker Replied March 29, 2023, 5:46 PM EDT
response: Thanks so much for the information.   On Wed, Mar 29, 2023 at 4:09 PM Ask Extension <<personal data hidden>> wrote:

responder: Answered by theHome and Garden Information Center (HGIC), University of Maryland Extension. For timely gardening information and tips, subscribe to our Maryland Grows blog and quarterly newsletter. Follow us on Facebook, Instagram, and YouTube. Replied March 30, 2023, 8:47 AM EDT
response: You're welcome.