Spruce spider mite eggs (peak egg hatch 172 GDD). Photo by USDA Forest Service Archive, USDA Forest Service, Bugwood.org.

Damage caused by spruce spider mite feeding (shows up during summer). Photo by USDA Forest Service – Northeastern Area Archive, USDA Forest Service, Bugwood.org.

Garlic mustard early. Photo by Nancy Fraley, USDI National Park Service, Bugwood.org.

A flowering garlic mustard plant. Photo by Dan Tenaglia, Missouriplants.com, Bugwood.org.

Forest understory invasion by garlic mustard. Photo by Leslie J. Mehrhoff, University of Connecticut, Bugwood.org.