White spots on your pachysandra bed indicate an infestation of euonymus scale. This pest uses piercing-sucking mouthparts to drain plant sap, causing injury. Euonymus scale is tough to control due to protective coverings that adults form, which render insecticides ineffective.
Immediate action isn’t required unless the infestation grows. Female scale insects overwinter and start laying eggs in late April. The eggs hatch into crawlers over two to three weeks. Male crawlers feed and mate with females under a waxy coating. A second generation appears from late July through August.
Control is most effective during the crawler stage. Next March, prune infested areas to eliminate overwintering females. Dispose of the debris with garbage or in a facility with hot composting to destroy the insects.
Crawler activity occurs from late May to early June and late July through August. Apply control measures during both periods. Use summer-weight dormant oil for better results.
For further plant advice, reach out to the Plant Information Service at the Chicago Botanic Garden via [email protected].
Tim Johnson, senior director of horticulture at the Chicago Botanic Garden, provides guidance on this issue.
Senators Reach Bipartisan Agreement on Permitting Reform 
Experts Warn of Critical Period for the Colorado River 
Future Cities: Ambitious Projects Aiming for Innovation and Sustainability 
Supreme Court Case Suncor vs. Boulder: Implications for Accountability in Climate Change 
Hawaii Faces Impact of Record El Niño Through Recent Hurricanes 
Efforts to Save the Endangered American Red Wolf