Texans love crape myrtles! And, why not? They have been reliable blooming ornamental trees that seem to love our hot summers and not so ideal soil. However, they now face an insect pest that blackens their lovely bark and reduces their beautiful blooms.
The new pest is crape myrtle bark scale, and its first noted appearance in the US was in 2004 at a commercial property in Richardson, TX. It hit McKinney, America’s crape myrtle city, in 2005. In 2014, entomologists identified the offending insect as Eriococcus lagerstoemiae, previously only found in China, Korea, and Japan. It is hypothesized that it was introduced to the US via an infected smuggled plant. As of early 2015, the pest has spread to at least seven additional states (Louisiana, Oklahoma, Arkansas, Alabama, Georgia, Tennessee, and New Mexico). There’s even a website dedicated to tracking its ugly march across the US, https://www.eddmaps.org/cmbs/distribution.cfm.
Sooty Mold and Scale
Scale insects are often overlooked because once mature they don’t move, look like plant parts, and are quite small. Try to find me now! These minute pests feed by sucking the sap out of plant tissues. Usually the first clue that crape myrtle bark scale is attacking is the presence of sooty mold. The sooty mold is attracted to the bugs’ sticky excretions. Sooty mold may also develop if the crape myrtle aphid is on your plant. However, if you also find white adult scales that ooze a pink blood when crushed, you’ve just encountered the crape myrtle bark scale, not aphids.
Scale Damage on Crepe Myrtles
So, how do these critters affect my crape myrtles? The good news is that even heavy infestations aren’t usually fatal. However, their constant sucking on the plant has significant aesthetic implications. A stressed tree won’t produce as many flower clusters and blooms. The scales’ sticky waste coats the bark and anything else under the tree. And, finally the sticky bark turns black with sooty mold.
How to Get Rid of Scale on Crepe Myrtle
Now that we’re aware of the invader, how do we control it? You can start by washing the trunk and any reachable branches with a soft brush and a solution of water and mild dishwashing soap. This will remove a good portion of the sooty mold, the female insects and their egg masses. Then, give Dallas Tree Surgeons a call and ask for our Crape Myrtle Care Plan. We know the best methods for controlling crape myrtle bark scale and will give your crape myrtle just what it needs to recover and get back to blooming beauty again.