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
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

QUESTION:

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.

ANSWER:

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

Should I purchase wax myrtle plants as liners or pots
July 18, 2011 - I want to buy some wax myrtle over internet.Place has wax myrtle "liners" They look very thin. Will these bushes grow quickly or should I spend more $ for 1 gallon plants. Just need a hedge fairly q...
view the full question and answer

Suitability of Monterrey oaks for small space in San Antonio
April 23, 2009 - I am purchasing a home and the existing owners have planted three Monterrey oaks in the back. It is a small yard and the trees are no more than 15 feet from the house.The trees back up to a fence that...
view the full question and answer

Small tree for yard in Columbia TN
November 16, 2009 - I have a somewhat small yard but the construction workers put a water and sewer drain in the middle of my yard. The sewer main is located on the far side of my property my width of yard is 60 feet wid...
view the full question and answer

Disappearing oranges from Satsuma orange in Austin
June 25, 2008 - I had many tiny future oranges on my Satsuma Orange Tree until a few days ago. Suddenly, all were gone except one. They weren't on the ground and the tree itself seems incredibly healthy. It is gr...
view the full question and answer

Plant identification of fern-like tree in Tennessee/North Carolina
June 17, 2011 - Was on my way to Hilton Head and noticed near the border of Tennessee and North Carolina, there was a tree standing about 4 feet tall. Thin straight trunk and at the very top was fern looking foliage...
view the full question and answer

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