Host an Event Volunteer Join Tickets

Support the plant database you love!

Q. Who is Mr. Smarty Plants?

A: There are those who suspect Wildflower Center volunteers are the culpable and capable culprits. Yet, others think staff members play some, albeit small, role. You can torture us with your plant questions, but we will never reveal the Green Guru's secret identity.

Help us grow by giving to the Plant Database Fund or by becoming a member

Did you know you can access the Native Plant Information Network with your web-enabled smartphone?

Share

Ask Mr. Smarty Plants

Ask Mr. Smarty Plants is a free service provided by the staff and volunteers at the Lady Bird Johnson Wildflower Center.

Search Smarty Plants
See a list of all Smarty Plants questions

Please forgive us, but Mr. Smarty Plants has been overwhelmed by a flood of mail and must take a break for awhile to catch up. We hope to be accepting new questions again soon. Thank you!

Need help with plant identification, visit the plant identification page.

 
rate this answer
1 rating

Tuesday - March 20, 2012

From: Austin, TX
Region: Southwest
Topic: Pests, Trees
Title: Leaf Galls on Live Oak
Answered by: Becky Ruppel

QUESTION:

Hi - I have a live oak tree that always seems to have thinner foliage than our other two. Upon closer examination today I found small brown balls all over the mature leaves. The balls look and feel very much like peppercorns. What is this, and is this a danger to the tree? I did read the other post about Woody oak twig galls but based on that post I don't think that is what is going on here. Thank you for your time.

ANSWER:

The tree in question sounds like it has leaf galls formed by the Mealy Oak Gall Wasp Disholcaspis cinerosa.  This wasp forms both stem and leaf galls depending on the stage in its life-cycle.  Galls are formed when an insect (in this case a type of tiny wasp) lays an egg just under the surface of a stem or leaf.  A gall is formed because the tree is stimulated by the presence of the egg, and eventually the hatched larvae, to grow a structure around the wounded area.  Galls are very common in oaks and are not considered harmeful to the health of trees.

For more detalied information about Mealy Oak Gall Wasp see the Mr. Smarty Plants post by Nan Hampton that talks about the specifics of the wasp, its reproduction, life-cycle, and affect on trees. 

The links in that post appear to no longer work. Below are updated links for the information cited in that answer about Mealy Oak Gall Wasps. 

"The Mealy Oak Gall on Ornimental Live Oaks in Texas"

"Gall Making Insects and Mites"

 

More Trees Questions

White ash trees with bunched up leaves from Nevada TX
June 09, 2012 - I have very young white ash trees (3' tall planted this winter) The leaves are crippled not opening up bunched up together and have a white powder. Is this aphids mites or what. Only on one tree. Th...
view the full question and answer

Best pine tree for northern Illinois
October 03, 2010 - I live in Schaumburg,IL. What would be the best type of pine tree to plant?
view the full question and answer

Are Chickasaw plums evergreen?
August 13, 2014 - Are Chickasaw Plums evergreens? I've been very interested in planting a few but some websites say they are evergreens while others say the opposite. Furthermore, would I have to plant a male and fema...
view the full question and answer

Is a Mexican plum planted last Spring in Houston ready to bloom
April 08, 2011 - I live in Houston, TX. I bought my Mexican Plum last late Spring. It was about 4' tall. It is now about 6' tall, very healthy with lots of beautiful leaves. It gets a lot of sun. It did not blo...
view the full question and answer

Leaves falling early from red oaks.
October 08, 2007 - The leaves on my Texas red oaks are dropping off prematurely. This usually doesn't happen until late November/early December. I'm wondering if it has something to do with our wet summer, or if I sho...
view the full question and answer

Support the Wildflower Center by Donating Online or Becoming a Member today.