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
3 ratings

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

Yellowing of St. Augustine grass in south Texas
June 04, 2009 - We live in deep south Texas, Roma, Texas to be precise and we have a problem with our San Augustine grass. In the spring its quite nice and green after a few weeks and one rain it is turning yellow.
view the full question and answer

Willow woes in Philadelphia, NY
August 22, 2010 - I have a 2 yr old willow; it is August and it looks like the tree has gone dormant, is this normal?
view the full question and answer

Strange growth on oak tree
August 26, 2008 - i have a very strange round segmented growth on a tree in my yard. i think the tree is a chinkapin oak and the growth is a reddish color. it looks like a ball with suction cups on it. it is very st...
view the full question and answer

How to correct Anacacho leaves that are turning brown and curling in Driftwood, TX?
May 11, 2012 - Anacacho lunarioides leaves are turning brown and curling,how do I correct?
view the full question and answer

Leaves turning brown in Fredonia KS
June 16, 2009 - Leaves turning brown.
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