Plant and Insect Diagnostic Clinic Update – August 25, 2017

News Article

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 


Lawn, Nigrospora blight, establishment issues

Turfgrass, Ascochyta leaf blight 


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


Lina Rodriguez Salamanca Extension Plant Pathologist and Diagnostician (Program Specialist II)

Dr. Lina Rodriguez Salamanca is an extension plant pathologist and diagnostician with the Iowa State University Plant and Insect Diagnostic Clinic, a member of the North Central Plant Diagnostic Network (NCPDN) and National Plant Diagnostic Net...