What is THIS on the leaves???

Jim Ginas
by Jim Ginas
I've been living in this area for almost 5 years and don't ever recall seeing the leaves of one of our trees looking like this! Infestion of WHAT??
what is this on the leaves, gardening
what is this on the leaves, gardening
what is this on the leaves, gardening
  18 answers
  • KMS Woodworks KMS Woodworks on Jun 26, 2012
    I looks like a "red pea" gall....these are formed by insects. http://en.wikipedia.org/wiki/Gall

  • Leah R Leah R on Jun 26, 2012
    Some years are worse than others. It's G&B (Grin and Bare It).

  • Val L Val L on Jun 26, 2012
    I also tend to lean towards gall. But being who I am, have you pulled any of them off to see what is inside? Also send the photos to co operative extension in your area.

  • Nicole G Nicole G on Jun 26, 2012
    http://waynesword.palomar.edu/pljuly99.htm Maybe this will help, there were several varieties of gall listed on the web page, with pictures.

  • Susan M Susan M on Jun 26, 2012
    I see it on southern pecan trees I am curious to know what it is too!

  • Kara C Kara C on Jun 26, 2012
    I googled the photo for you and found this: "Life in the garden takes many shapes and sizes but one of the strangest is galls. Galls are abnormal growths on a plant caused by a parasite. I found these galls on a fallen oak leaf today. The doughnut shaped ones are Silk Button Galls (Neuroterus numismalis) and the green-coloured ones are Common Spangle Galls (Neuroterus quercusbaccarum). They are tiny. The diameter of the Silk Button is about 3 mm. They are created when the tiny Cynipid wasp lays eggs on the oak leaf. The grub matures inside the gall." from http://english-country-garden.blogspot.com/2009/10/silk-button-and-common-spangle-galls.html

  • Amy C Amy C on Jun 26, 2012
    I have also seen it here in western PA and have no idea what it is.

  • Susan B Susan B on Jun 26, 2012
    I have these but the weird part is I can't figure out where they are coming from because the leaves don't match any of my trees

  • Walter Reeves Walter Reeves on Jun 26, 2012
    The bumps are harmless insect galls growing on the leaves. The galls are caused by pecan phylloxera, aphid-like insects that emerge in spring and infest leaves and twigs. Big populations of this insect can cause loss of the pecan crop for the current year and also the following year. If you only enjoy your tree for its foliage and not the nuts, nothing needs to be done. Phylloxera populations vary widely from year to year, depending on weather and predators.

  • Jim Ginas Jim Ginas on Jun 26, 2012
    Thank you all. So follow up question is do we just ignore them and the winter will / SHOULD kill them off, or should we have the woods behind our house sprayed?

  • Yolanda W Yolanda W on Jun 26, 2012
    its a scale insect.

  • Douglas Hunt Douglas Hunt on Jun 27, 2012
    Jim, I wouldn't spray. I could be five years before you see it again.

  • Jim Ginas Jim Ginas on Jun 27, 2012
    @ Doug: Thank you, as always! If this is only a once every few years and they aren't doing any harm, we can just live with them. I haven't seen any insects or anything, so maybe the other insects and animals are eating them!

  • Pam K Pam K on Jun 28, 2012
    we had this on our maples in central Mich. We were told that it was insect galls and not to do anything. Probably wouldn't reoccur the next year, and they were right.

  • Jim Ginas Jim Ginas on Jun 29, 2012
    @ Pam: and ODD thing is these are ONLY on ONE type tree (leaves), all other trees in the yard are free of these things!

  • KMS Woodworks KMS Woodworks on Jun 30, 2012
    Jim this is not as odd as you may think...many bugs have host / parasite relationships with single species. Stem rust is a disease that has an "intermediate host" http://en.wikipedia.org/wiki/Stem_rust Getting rid of only one part of the cycle generally helps control the situation

  • Jim Ginas Jim Ginas on Jul 01, 2012
    @ KMSD: thanks....

  • Patricia Patricia on Aug 07, 2016
    Looks like Leaf Galls

    • Jim Ginas Jim Ginas on Aug 14, 2016
      haven't seen these this year, until today.. just a few leaves, but that means they are back...