elm

Zig Zag Sawfly adults have been trapped this week emerging in Central Ohio.

Secrest Arboretum in late April and early May is a glorious sight to behold, from buckeyes to Crablandia, from sweetgum flowers to cedar rusts. Enjoy!

The names of plant diseases, plant pests, and even human disease matter. This Point Counter Point will start a series on narrating why these things should matter to BYGL readers.

Jim Chatfield and I visited the USDA Forest Service, Northeastern Research Station, in Delaware, OH, on Monday where they are waging a battle to eliminate Elm Yellows (EY) from their American Elm Restoration Project research plots.  I last saw the disease in southwest Ohio in 2013. 

The problem is that American elms (Ulmus americana) that are resistant to Dutch Elm Disease (DED) have no known resistance to Elm Yellows (EY).  DED is caused by a fungal infection; EY is caused by a phytoplasma which is a type of bacterium.  DED fungi plug the xylem.  The EY phytoplasma...

I recently looked at some elms on Columbus city streets and took some images of two insects on one leaf, though mostly on lower leafs and trunk sprouts. One insect was a wasp leafminer, Fenusa ulmi.  The larvae of this insect “mine” plant leaf cells for their nutritive value. It is a native insect and generally is worse on non-native elm species and those hybrids with some Asian or European elm genetics. Typically, insecticides are not recommended but labeled systemic insecticides may be useful in situations where applications are warranted.

 

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It is often said that a picture tells a thousand words. In this case, perhaps a few less, but it does tell multiple and layered stories. First, as shown by this image, one of the plant ID characteristics of elm (Ulmus) leaves is the uneven base to the leaf blade as shown here. This was the main point for the attendees at a recent Name That Tree program of OSU Extension at the OSU Mansfield campus. Secondly, of all the gall, the elm cockscomb gall insect (Colopha ulmicola) induced the DNA of this elm leaf to produce a proud new home for the insect’s progeny. Thirdly...