Plant and Insect Diagnostic Clinic Update- January 7, 2009

Thank you to the numerous clients and friends around the state who contacted the Plant & Insect Diagnostic Clinic in 2008.  It is always good to hear from you.  Please keep those letters, phone calls, e-mail messages and samples coming!  We look forward to serving you in the coming year.

The PIDC provides many services.  We diagnose plant problems from disease, insect, or abiotic factors. We identify mushrooms, insect, plants (including weeds).  We also process soil samples for corn nematodes or soybean cyst nematode egg counts. 

Please contact us at:

Plant & Insect Diagnostic Clinic
327 Bessey Hall
Ames, IA  50011


The following are a few of the samples or questions received the past month.


We frequently mention yellowjacket wasps as beneficial predators, pests at picnics or home invaders when they nest in wall voids and attics. We have also explained how these small (one-half inch long) yellow and black wasps are related to baldfaced hornets and that both make papier-mache nests out of wood pulp and wasp spit. Baldfaced hornets produce nests outdoors on trees, posts and houses. Yellowjacket wasps build nests inside existing cavities such as holes in the ground or building walls, in decayed logs and stumps or hollow tree trunks. Seldom do we get to see the yellowjacket wasp nests, and especially not of the size of the one in the photo below, taken by Thomas Smith in central New York state after discovery during attic renovation. The nest measures 44" high and 24" wide at the base. Most impressive. Yellowjacket wasps nests are annual. That is, they are used for only one summer (May to October or November) and then never used again. Nests are empty by this late into the winter, so there is no need for control at this time. The nest can safely be scraped down and discarded.

Yellowjacket wasp nest in attic.  Photo by Thomas Smith.Yellowjacket wasp nest in attic. Photo by Thomas Smith.


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