Plant and Insect Diagnostic Clinic Update – August 25, 2017

The following are highlights and updates about samples and questions recently received in the Plant and Insect Diagnostic Clinic. Visit the PIDC's Facebook page for updates and more pictures. For more information on a particular disease or insect problem listed, follow the article linked.


Plant Diseases and Insect Damage


The following highlights represent recent sample submissions from fruit, vegetables, trees and ornamental plants.


Broadleaf Trees


Bur oak, Two lined chestnut borer  


Bur oak, Bur oak blight



Symptoms of Verticilllium wilt in coneflowers
Symptoms of Verticilllium wilt in coneflowers

Various Oaks, anthracnose, Eriophyid mite galls, powdery mildew, oak bullet galls, oak tatters, Botryosphaeria twig blight


Pin oak, vein pocket gall


Maple, transplanting stress, for newly planted trees care keep in mind the recommendation on the publication Community Tree Planting and Care Guide


White Ash, Verticillium wilt 


Coniferous Trees


Pine, Pine wilt, Woodboring insect damage


Scotch Pine, Zimmerman pine moth damage 


Spruce, Rhizosphaera needle cast, Stigmina needle cast, Spruce needle miner, Phyllosticta needle blight



Signs (fungal structures) of Verticilllium wilt in coneflowers
Signs (fungal structures) of Verticillium wilt in culture. On the right, cells starting to form sclerotia -resting structure

Crabapple, Cedar apple rust 


Perennials and Annuals


Coneflower, Verticillium wilt   


Hosta, sunscald 


Dogwood, Dogwood Leaf Spot


Highbush Cranberry, Anthracnose 


Willow, Botryosphaeria canker 


Turf


Lawn, Nigrospora blight, establishment issues


Turfgrass, Ascochyta leaf blight 


Vegetables


Bell Pepper, Sunscald, Blossom end rot 


Fruit (small and tree fruit, including hops)


Hops, Alternaria cone disorder 


Ornamental Pear, suspected fungal cankers 


Cherry, suspected decline. see publication Understanding Decline in Trees 


 


Household and Other Insect Pests


Wood cockroach 


Larder beetles


 


Plant Identification


Quackgrass, see the article Quackgrass was the big winner in drought

Authors: 

Lina Rodriguez Salamanca Extension Plant Pathologist and Diagnostician

Dr. Lina Rodriguez-Salamanca is a diagnostician and extension plant pathologist with the Iowa State University Plant and Insect Diagnostic Clinic  (clinic.ipm.iastate.edu), a member of the National Plant Diagnostic Network (NPDN, ...

Links to this article are strongly encouraged, and this article may be republished without further permission if published as written and if credit is given to the author, Horticulture and Home Pest News, and Iowa State University Extension and Outreach. If this article is to be used in any other manner, permission from the author is required. This article was originally published on August 25, 2107. The information contained within may not be the most current and accurate depending on when it is accessed.