Rizosphaera needlecast on Norway spruce.

Rizosphaera needlecast on Norway spruce, closeup. Rizosphaera photos by: Nancy Gregory, University of Delaware.

Woolly beech aphid. Photo by: Whitney Cranshaw, Colorado State University, Bugwood.org.

Heavy pine bark adelgid infestation. Photo by: USDA Forest Service – Northeastern Area Archive, USDA Forest Service, Bugwood.org.

Light infestation of pine bark adelgids. Photo by: Brian Kunkel, Ornamentals IPM Specialist, University of Delaware.

Boxwood leafminer adult and blistered leaf. Photo by: John A. Weidhass, Virginia Polytechnic Institute and State University, Bugwood.org.

Boxwood leafminer larvae. Photo by: Nancy Gregory, Plant Diagnostician, University of Delaware.