Rent Shop Volunteer Join

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 Pests Questions

Failure to thrive of Lantanas
August 06, 2008 - Here at work we have 4 beautiful yellow Santanas(should I say had), the leaves have started to turn brown and no longer blooming. Appears to have a fungus or disease. Please help!
view the full question and answer

Weeping Willow Problem in Texas
September 04, 2014 - Our weeping willow's leaves are turning yellow and falling off. We are also seeing some brown, gnarly looking pods on some of the stems can you tell us what's happening?
view the full question and answer

Sap drips from Sophora secundiflora
May 30, 2008 - We have an old Mountain Laurel (sophora secundiflora) about 20 ft tall. It blooms pretty well and seems healthy. We are wondering why it drizzles a non-sticky sap in tiny drops. Hold out your hand and...
view the full question and answer

Pill bugs in potted plants in Atlanta GA
June 14, 2013 - Hello, I repotted four aloe vera plants two days ago with a cacti soil and watered them thoroughly in terra cotta pots according to directions on the bag. Well the next morning the pots had pill bug...
view the full question and answer

Petals not developing on blackeyed susans from Nashville TN
July 05, 2011 - I have an established "patch" of black eyes susans. This year, the leaves are beautiful, the centers black..but the petals are practically non existent. They didn't seem to develop correctly. Any...
view the full question and answer

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