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 cited.
Plant Diseases and Insect Damage
The following highlights represent recent sample submissions from fruit, vegetables, and ornamental plants.
Broadleaf Trees
Pin Oak, Oak Wilt
Bur oak, Bur Oak Blight
Pin Oak, Horned oak gall
Catalpa, Suspected abiotic scorch
River Birch, suspected nutritional deficiency and decline. see Nutrient/Soil pH Imbalances
Maple, Wood boring insect damage
Magnolia, Verticillium Wilt
Walnut, walnut caterpillars
Coniferous Trees
Eastern White Pine, Phomopsis tip blight, see article from University of Illinois Extension
Spruce, Rhizosphaera Needle Cast
Spruce, Black Hills Spruce, Pine, suspected abiotic disorder
Spruce, Spruce spider mite
Black Hills Spruce, Spruce, Stigmina needle cast
Perennials and Annuals
Marigold, blossom rot, botrytis blight. see Gray mold
Hosta, Fusarium crown and rot rot, bacterial soft rot
Turf
Lawn, Nigrospora blight
Lawn, Curvularia leaf blight
Lawn, establishment issues
Vegetables
Cucumber, anthracnose, see University of Minnesota article on cucurbit anthracnose
Tomato, Suspected Juglone toxicity, see University of Wisconsin article on Black Walnut Toxicity
Fruit (small and tree fruit, including hops)
Ornamental Pear, Fire Blight
Pear, Pear leaf blister mite
Apple, Apple Maggot damage
Strawberry, Pythium root rot, Fusarium crown rot
Household and Other Insect Pests
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, Yard and Garden, 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 11, 2017. The information contained within may not be the most current and accurate depending on when it is accessed.