Native Plants
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.
Did you know you can access the Native Plant Information Network with your web-enabled smartphone?
Ask Mr. Smarty Plants is a free service provided by the staff and volunteers at the Lady Bird Johnson Wildflower Center.
rate this answer
Wednesday - May 12, 2010
From: Austin, TX
Region: Southwest
Topic: Diseases and Disorders
Title: Red-backed bugs on mountain laurel (Sophoro secundiflora)
Answered by: Nan Hampton
QUESTION:
I found red-backed bugs (in fact two end-to-end like the east Texas love bugs) on my mountain laurel which has been losing leaves. Are these bugs the culprit?ANSWER:
Sophora secundiflora (Texas mountain-laurel), according to the US Forest Service "...are primarily pest-free, except for infestations by caterpillars of a moth in the family Pyralidae." The moth is Uresiphita reversalis (Pyralid moth or Genista broom moth). You would see the caterpillar and its damage from chewing on the leaves if they were infesting the plant. Obviously the bugs aren't the caterpillars and since there don't seem to be any other serious insect pests I don't think the bugs are the culprit. The Forest Service site does mention that the mountain laurels are especially susceptible to phenoxy herbicides. One of the commonest of these phenoxy herbicides is 2,4-D. These particular herbicides are used against broadleaf weeds on grass lawns, pastures or in grain fields. The problem is that they are very volatile and can drift for miles with the wind and effect plants far from their application. They have been especially detrimental to grapevines. If you or your neighbors have been using any of these on your lawns, it is possible that some has landed on your mountain laurel and is causing the problem.
Another possibility is that you have had some environmental change where the plant is growing. Mountain laurels like well-drained soil to grow in. They don't like having 'wet feet'. Has the drainage in its vicinity changed? Is there the possibility that the soil has become compacted by a lot of traffic—foot or vehicle? If you think that this has happened, you need to remedy this by stopping the traffic and adding a hardwood mulch over the soil surrounding the tree. It will help protect the roots and eventually work its way into the soil and relieve the compaction. Better yet, you could carefully work some of the mulch into the soil so that when the tree does get water (from rain or supplemental watering) the water gets to the roots and doesn't stand on top of them. Whatever you do, don't fertilize the tree. In the first place, native plants don't need fertilizing and a plant under stress (as yours seems to be) should never be fertilized.
More Diseases and Disorders Questions
More trees to go with live oaks in Schertz TX
July 13, 2010 - We moved to a new house that has two recently planted live oak trees. Other than those two little trees there is nothing else on the property. Because of what I read about the oak wilt I would like ...
view the full question and answer
Problems with dogwood tree in Jacksonville FL
February 28, 2010 - Sir, I believe I have a Cornus drummondii, a stiff dogwood tree on my lawn which a few years ago was big, lush and full of branches and leaves. In the last 2 years I have noticed about 80% of it drop...
view the full question and answer
Problems with hibiscus in Florida
November 09, 2008 - Have a hibiscus in Florida. It has always done beautifully planted in the ground. This year, it has developed something where the branches are sort of white, and the buds (and ends of branches) look ...
view the full question and answer
Adventitious sprouts from Live Oak in Dallas
February 26, 2011 - How do I kill Holly growing in my yard? I have a Live Oak tree growing in my Bermuda grass lawn. The holly grows under the tree from the trunk extending out about 12-15 ft. It grows right in with the ...
view the full question and answer
Problems with non-native citrus trees from Mesa AZ
January 13, 2014 - We have one valencia orange tree and one naval orange tree in our Mesa, AZ yard. Just noticed some oranges on both trees have a 1/4 inch diameter hole through the skin and the orange fruit and skin a...
view the full question and answer
Support the Wildflower Center by Donating Online or Becoming a Member today. |