Plant and Insect Diagnostic Clinic Update - July 15, 2016

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.


Millipedes by the Millions!  Or at least that's what callers claim.  Read more about millipede migration in the September 26, 2014 issue of the Horticulture & Home Pest News.



Broadleaf Trees

In the past two weeks, we have received several samples of elms. Keep your eye peeled for yellowing and wilting (droopy look) of the leaves and dieback on elms. If you see these symptoms on your tree, your elm may be suffering from Dutch elm disease. For information on the type of sample required for diagnosis, visit our Dutch elm disease website.


When planting a new tree simple but helpful cultural practices such proper watering and mulching can positively impact the longevity of the tree.  See details on new tree establishment in the Horticulture & Home Pest News from May 26, 2010.

Coniferous Trees

We diagnosed several cases of Diplodia tip blight in non-native pine (mainly Austrian and Scotch pines).  See information on symptoms and the information on the type of sample needed for confirmation at the Clinic's website.  


Rainy and humid weather has contributed to the development of plant diseases in vegetables. We gave confirmed pepper bacterial spot and Septoria leaf blight.


We received several garlic samples showing symptoms and signs of Botrytis rot, anthracnose, purple blotch, and rust. When sending whole plants, follow the example on this of this customer who took the time to ensure the remaining soil in the root system was contained at all times during transit. Bagging the root ball holds any soil on the root ball from spilling on the foliage and keeps the sample as intact as possible. 

When collecting a whole plant, bag the root ball to keep soil contained during transit (see examples in left and middle pictures). Right: Garlic rust symptoms. Photo by Lina Rodriguez Salamanca, Plant & Insect Diagnostic Clinic


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  (, a member of the National Plant Diagnostic Network (NPDN, ...

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