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?


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
Not Yet Rated

Friday - May 30, 2008

From: Austin, TX
Region: Southwest
Topic: Trees
Title: Insect attack on bur oak (Quercus macrocarpa)
Answered by: Nan Hampton


Something is attacking the bur oak that was planted in 2007. Insects are not on the leaves, but the edges of some leaves look chewed back. Others look brown around the edges. Do you have any idea what we are dealing with here, so that we may treat the tree? Thanks.


According to an article from the Florida Cooperative Extension Service by E. F. Gilman and D. G. Watson, Quercus macrocarpa (bur oak) is pest resistant. They say: "Pest resistance: long-term health usually not affected by pests" and "No pests are normally serious." They do list various insects that sometimes attack the bur oak. Of the ones they list in the article, the gypsy moth (Lymantria dispar), the oak leafmining sawfly (Profenusa lucifex) and oak kermes, or scale insect, (Nanokermes pubescens) sound as if they are the most likely suspects. According to the article, gypsy moths feed mainly at night and find a place to hide out of the sun during the daytime. If you have a small infestation, this may be why you haven't seen any caterpillars. The gypsy moth article offers advice about control of these insects.

The only photos of the damage caused by the oak leafmining sawfly (Profenusa lucifex) is in French from PHYTO Ressources from Canada. A loose translation of the article is that Profenusa lucifex "is a small fly, whose yellowish-white larva burrows mines between the leaf veins, producing a brown stain on the top surface of the leaves from mid-June till the end of July. Normally, there is a single generation per year. Sometimes there is a second generation that is active in the autumn, but the mines are less numerous. There is no description of the life cycle. It attacks all oak species (Quercus spp.). No control methods, either cultural or chemical are known." There are photos showing the damage on Quercus coccinea (scarlet oak).

Nanokermes pubescens (syn.=Kermes pubescens) is a tiny, nondescript insect that can easily be overlooked. The article, "Scale Insects on Shade Trees and Shrubs" from Purdue University gives more information, photos and control methods.

In an article from the US Forest Service several other pests are named, but none that are named seem to match the damage you see on your tree. The pests are:

Variable oakleaf caterpillar (Heterocampa manteo)

Redhumped Oakworm (Symmerista albifrons)

Phyllophaga spp. attack roots

Oak lace bug (Corythucha arcuata)

Apparently, the bur oak is the only host plant for the oak skeletonizer (Bucculatrix recognita), but there are no photos available on the web of the insect or the damage it does.

If you think your bur oak is in imminent danger, my advice is to contact a certified arborist who can look at it to determine what is causing the problem and offer a solution.


More Trees Questions

Texas persimmon with scorched leaves from Austin
July 11, 2013 - I planted a Texas Persimmon seedling (five gallon) in my yard in early April. It is in a sunny, well-drained spot, and I have watered it regularly since planting. All was fine until the last weekend i...
view the full question and answer

Selection of trees for new home
June 30, 2008 - We are moving to Roanoke, Texas(Denton County) into a new home. Our home will have 3 trees which we can choose. They are Texas Ash, Live Oak, Sweetgum, Silver Leak maple, Cedar Elm and Bradford Pear...
view the full question and answer

Further explanation of retaining walls and trees from Washington MO
March 11, 2013 - I had a question previously about putting retaining walls across the root system of a 40' tall bald cypress tree(not like spokes on a wheel, but concentric to tree trunk). How wide can the walls be? ...
view the full question and answer

Why are my potted Prunus caroliniana plants shedding leaves in LA, CA?
May 02, 2011 - I bought Prunus caroliniana in pots to use as privacy fence on my balcony. Have had them for about 6 weeks and they are shedding a lot of leaves. Some leave are drying out and others have what ...
view the full question and answer

Brown spots on native oak trees
June 16, 2015 - Hi, My native live oak trees are declining. The leaves have small brown spots that increase in size until the leaf dies and falls off, then the branch and then the entire limb. I have not watered the...
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.
© 2015 Lady Bird Johnson Wildflower Center