Leaf "blister" on tree - Ask Extension
Hi I have a tree which has many leaves covered with these strange shaped blisters. There's a small worm inside some of them, and some tiny bugs. Can y...
Knowledgebase
Leaf "blister" on tree #338814
Asked July 02, 2016, 5:05 PM EDT
Hi I have a tree which has many leaves covered with these strange shaped blisters. There's a small worm inside some of them, and some tiny bugs. Can you help me identify them? And, are they a danger to the tree?
Montgomery County Pennsylvania
Expert Response
The tree appears to be an elm and the structure is a gall. Probably the elm cockscomb gall aphid
See here to determine if it matches what you are seeing (and for more info)
See here to determine if it matches what you are seeing (and for more info)
- http://www.extension.umn.edu/garden/diagnose/plant/deciduous/elm/leavesprojections.html (scroll down to 2nd set of pictures)
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http://bugguide.net/node/view/356914
