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.
The following are plant diseases and insect damage highlights of last month's sample submissions from fruit, vegetables, and ornamentals.
Red oak, Oak wilt, suspected physiological scorch
Bur Oak, Bur oak blight
White oak, Two lined chestnut borer
Hickory, Hickory scab, mites, suspected decline
Arborvitae, Suspected transplant/establishment issues, Bark beetle damage
Norway Spruce, Rhizosphaera needle cast,
Perennials and Annuals
Ninebark, Rhizoctonia root rot
Dracaena, Bacterial leaf spot. To learn about management of bacterial disease on foliage plants, see this resource form University of Minnesota
Cape Primrose, INSV (Inpatients necrotic spot virus)
Tomato, spider mite damage
Swiss Chard, Pythium root rot
Garlic, Dry bulb mite
Fruit (small and tree fruit, including hops)
Raspberry, Crown gall
Apple, Sooty mold due to insect activity
Plant, mushroom, and insect identifications:
Mycena sp., Lepiota sp. Lepiota mushrooms are one of the various fungi that may be present in lawns as fairy rings.
Puncture vine (Tribulus terrestris). Puncture vine is typically found in sandy or compacted soils and disturbed sites. Common sites are along roadsides and railroad tracks, pastures, and waste areas. Puncture vine is not widespread in Iowa and is most often found in the southern half of the state.
Termites are a serious structural pest. It is important to correctly identify termites or their damage and work with a pest management company to treat them.
Six-spotted tiger beetles are commonly submitted as suspect emerald ash borers because they are iridescent green. Luckily six-spotted tiger beetles are beneficial predators and will not harm trees.
Bed bugs are unfortunately a very frequent sample in the clinic.