Question
Omaha, Nebraska

Has Maple Bladder Gall Disease been found/identified on Elm trees before?  

I will swear as a yard novice that my Homestead Elm, planted in my yard in 2004, has MBGD.  The bladders are a few millimeters protruding and cycle from light green to pink to red to black.  All of my Internet searching only points to this disease.  

I do have 3 50+ foot tall Silver Maples 30, 60, and 100 feet away from the young Elm.

Do you have some other disease that meets the description I gave?

Answer
Elm has a different leaf gall called a finger gall that looks very similar to the ones on maple but no the same insect or mite. The gall is called the Elm Finger Gall and it's caused by a mite called Eriophyes ulmi. And we all know that mites aren't insects, but rather are related to eight-legged ticks and spiders!
It does not cause any real health problems for the tree so treatment is not usually recommended.
these gall makers secrete a chemical that causes the leaf cells to form around their eggs protecting them. They can be controlled using insecticides especially soil applied systemic insecticides such as merit but these are costly and generally not worth the effort since the galls do not damage the tree except for possibly causing premature leaf drop.   

Here is web link to more information on gall makers.
http://agrilifebookstore.org/tmppdfs/viewpdf_210.pdf?CFID=1644889&CFTOKEN=379e2e...