white tiny ? all over the bark of bush
This looks like Euonymus scale, and yes, it is harmful in severe cases. Scales are tiny insects that suck out the plant sap, which can lead to overall plant decline. On the following page of our website, you will find information about Euonymus scale and the various options you can use to manage them. A horticultural oil spray or insecticidal soap can be used to control them in the summer. https://extension.umd.edu/hgic/topics/euonymus-scale-shrubs
Please be aware that these burning bush shrubs have become problematic in some natural areas of Maryland due to their invasiveness. https://extension.umd.edu/hgic/topics/burning-bush If the scale is difficult to control and continues to be problematic, we encourage you to consider a native plant for replacement. Several options and resources are listed on our website (https://extension.umd.edu/hgic/topics/native-plants) and we are always happy to assist with plant recommendations if needed.