Type of tree and possible bug

Question: What tree is this and what are these little cocoon looking things on the tree leaves?

responder: Jane MacKnight  Replied May 29, 2024, 11:03 AM EDT
response: Hi Jak: Thanks for including the photos. While it's a bit difficult to see detail in the close-up of the leaves and insects, it is an elm tree which makes me think the insect may be the European elm flea weevil, European Elm Flea Weevil | Ohioline (osu.edu). The factsheet provides some information about treatment but also recommends contacting your local, Franklin County extension agent. Alternatively, you could contact Curtis Young in Van Wert County who wrote the article or Joe Boggs in Hamilton County who is an entomologist. You may want to contact Franklin County Urban Forestry since the tree appears to be on public property. Typically, the county urban forestry department is responsible for health and management of trees on public property. Good luck.

responder: The Question Asker Replied May 29, 2024, 2:26 PM EDT
response: Thanks for the information.  I agree that the tree is most likely an elm and apologies for not getting a better picture.Also, it is a tree that was planted by the city.I also need to apologize for calling the things on the leaves bugs.  Now that I've looked a bit closer, they appear to be more like growths and not bugs.  I took a look at the European elm weavil you had described.  I didn't directly observe anything that looked like that bug, just growths.  Also, given the number of growths on the leaves throughout the tree there were very few leaf holes.  There were some, but didn't seem to have the number or "blotch mines" as described here "https://extension.umn.edu/yard-and-garden-insects/european-elm-flea-weevil".  So apologies if this ended up being a red herring.If you believe it still could be the weevil, please let me know.I've seen people refer to them as galls.  What do you think?On Wed, May 29, 2024, 11:03 Ask Extension <<personal data hidden>> wrote:

responder: Jane MacKnight  Replied June 05, 2024, 7:47 AM EDT
response: Thanks for the clarification. It's good news that it's not the weevil which can be destructive. Galls are pretty common and in general do not harm the tree. They are usually caused by an insect, wasp, fungi etc. I believe galls can be formed by the tree itself in response to the whatever organism is on the tree. There is a huge range of galls. The elm tree should be fine.

responder: The Question Asker Replied June 05, 2024, 9:17 AM EDT
response: Thanks for the information.  Is there anything I can do or spray to prevent the galls?On Wed, Jun 5, 2024, 07:47 Ask Extension <<personal data hidden>> wrote:

responder: Jane MacKnight  Replied June 05, 2024, 9:29 AM EDT
response: Jak -- If these are galls -- they could also be an insect cocoon or other developmental stage of an insect -- they generally do not harm the tree. And the insect that they harbor may be beneficial to the tree or ecosystem.  You might take a leaf or small twig to a nursery or landscaper to get a more specific identification. A good nursery ought to be able to identify and advise on remedies if any are needed. Regards, Jane

responder: The Question Asker Replied June 05, 2024, 9:57 AM EDT
response: Thank you for answering my questions. You can go ahead and close the case.On Wed, Jun 5, 2024, 09:29 Ask Extension <<personal data hidden>> wrote: