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 to ask questions and for updates and more pictures. For more information on a particular disease or insect problem listed, follow the article cited.
The following plant disease highlights represent recent sample submissions from fruit, vegetables, and ornamentals.
Poplar- Marssonina leaf blight, see US Forest Service factsheet at Marssonina Leaf Blight
Spruce- Sudden Needle Drop
Black Hills Spruce- Stigmina needle cast
Perennials and Annuals
Lily- Daylily Leaf Streak , resource from Clemson
Creeping Bentgrass- Anthracnose
Creeping Bentgrass- Nematodes (ring and lance nematodes)
Fruit (small and tree fruit, including hops)
Grape-grape downy mildew and grape black rot
Raspberry- cane blight, see the Ohio State University resource on cane blight
In the past month Iowans have rediscovered or newly discovered the joys of Japanese beetles! These voracious beetles feed on a wide variety of plants. Commonly damaged are linden, birch, roses, and grapes. Beetles emerged in late June and they will live about 6 weeks. Some areas are reporting populations decreasing, while in others things are still going strong. We are hearing from locations in the western half of Iowa that this is the first time they have observed such extensive damage. Read more about Japanese beetles in the July 14, 2017 issue.
We have received several bat bug samples this summer. Bat bugs look very similar to bed bugs, but have longer body hairs. Close magnification is needed to distinguish between the two species. Bat bugs feed on bats and are found in homes with bats roosting. Bat bug control requires preventing bats from roosting in the attic. Please see this article on bat exclusion.