I have about 10 Euonymus (Emerald Gaiety) in my yard. A few have had a powdery substance on them. One of those is now 95% dead. The leaves turn from green to white, then brown/dead. I see no insects/leaves eaten. I have trimmed off dead areas before, and more occurs each year. 1) What disease is this? 2) If I just take out the dead one & replant a new one, will this "disease" continue?

Hi,

Without a sample I can only guess as to what you mighta have and the most common and most destructive pest on euonymous is scale which will cause defoliation and result in "white" areas on the leaves and stems. for heavy infestations it is best to remove the shrubs as sprays are somewhat effective but not really good on bad cases. If you do need to replant you will need to watch the plant closely and at the first signs of scale you can apply something like Bayer Advanced Tree and shrub caare or Orthene, or Bonide systemic insect control. Best time to apply is in early June.