En EspaŅol

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
Can't find the answer in our existing FAQs, submit a question to Mr. Smarty Plants.
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 Pests Questions

Protection of Mountain Laurel from Pyralid or Genista moth caterpillars
May 28, 2006 - I have a Texas Mountain Laurel. Every year it is attacked by caterpillars. They form a bag for lack of a better word on the ends of the branches destroying the blooms for the following year. PLEASE...
view the full question and answer

Weedy buffalo grass from Dripping Springs, TX
March 07, 2013 - I have a buffalo grass lawn. It is thin and filled with weeds. I would like to find a solution to improve my lawn. I prefer a native grass but I need to be able to control the weeds and I am not ph...
view the full question and answer

Dog-proof grass from The Woodlands TX
April 26, 2013 - I am looking for a hardy grass that can tolerate female dogs urine. Zoysia was suggested but I am concerned about it being invasive. Any suggestions?
view the full question and answer

Mealy bugs on plants in Washington, DC
July 07, 2011 - Dear Mr. Smarty Plants, There is this white stuff, looking like snow flakes, that is attacking my office plants. I use gasduster to blow it off of them, but that does not stop it from reappearing. Wh...
view the full question and answer

Controlling sandburs from Austin
February 24, 2013 - Hello, What is the best way to prevent sticker burrs from growing in a rocky bed with no grass. There are many other plants we want to preserve and a drip line to keep them watered. We have 2 small k...
view the full question and answer

Smarty Plants's Facebook profile Support the Wildflower Center by Donating Online or Becoming a Member today.

Mr. Smarty Plants wants you to be his Facebook friend. Click the Facebook icon to add yourself to Mr. Smarty Plants list of friends.
E-NEWSLETTER | BECOME A MEMBER | DONATE NOW | MEDIA | SITEMAP | STAFF
© 2015 Lady Bird Johnson Wildflower Center