Category Archives: Plant pathogens

Disease Hotline Issue 4

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Damage and symptoms of pine wilt nematode. Photo by: Robert Lambe, Virginia Polytechnic Institute and State University, Bugwood.org.

Close-up of damage, one year after tree death. Photo by: USDA Forest Service – Rocky Mountain Region Archive, USDA Forest Service, Bugwood.org.

Cerambycid (Longhorn) beetles transmit the nematode to susceptible trees. Photo by: L.D. Dwinell, USDA Forest Service, Bugwood.org.

Nematode in an axial resin canal of Pinus densiflora. Photo by: Y. Mamiya, Bugwood.org.

The nematodes also feed on blue stain fungi which often invade dead, dying, or fresh cut timeber. Photo by: USDA Forest Service – North Central Research Station Archive, USDA Forest Service, Bugwood.org.

What’s Hot HL Issue 23

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Cercospora leafspot on rose. Photo by: Bob Mulrooney, Plant Pathologist, University of Delaware

Pyracantha scab on fruits. Photo by: Bob Mulrooney, Plant Pathologist, University of Delaware

Puss caterpillar. Photo by: Gerald J. Lenhard, , Bugwood.org

Puss caterpillar. Photo by: Lacy L. Hyche, Auburn University, Bugwood.org

Plumbago foliar nematode. Photo by: Bob Mulrooney, Plant Pathologist, University of Delaware

Disease Hotline Issue 20

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Foliar nematode infesting hosta. Photo by: Bob Mulrooney, Plant Pathologist, University of Delaware

Foliar nematode infesting peony. Photo by: Bob Mulrooney, Plant Pathologist, University of Delaware

Plumbago foliar nematode. Photo by: Bob Mulrooney, Plant Pathologist, University of Delaware

Foliar nematodes infecting hosta. Photo found at:http://www.extension.umn.edu/yardandgarden/YGLNews/YGLNewsSept12007.html and taken by: Michelle Grabowski.

Sclerotium rolfsii (southern blight). Photo taken by: Nancy Gregory, University of Delaware Plant Diagnostician.