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

Thursday - July 14, 2011

From: Deerfield, WI
Region: Midwest
Topic: Pests, Trees
Title: Tree with brown spots on leaves containing caterpillars
Answered by: Nan Hampton, Eric Beckers, and Mike Quinn


We have a new little tree we planted in our yard and I went over to admire it and on each leaf there is a brown spot in which little worms are living. They are alive and moving around in the pocket the brown on the leaf has made for them. I showed my husband and he immediately cut the tree down and burned it, but I've never seen anything like this before and I'd like to know the name of the tree disease.


Technically, your tree's problem was an insect infestation, not a disease.  I consulted with a tree expert with the Texas Forest Service and an entomologist and both agree that your tree was infested with insects called leaf miners.  The little worms you saw were the larvae of the adult insect.  The adult female insects stick their ovipositors through the surface of the leaf and lay their eggs there.  The tiny larvae hatches and feeds on the leaf tissue layer between the upper and lower surfaces. The insect might be a moth, a beetle, a fly, a wasp, etc.   If you had told me what kind of tree it was, I might have been able to be more specific as to what kind of insect the culprit was.  Here is information about oak leafminers, the birch leafminer in Wisconsin, and the spotted tentiform leafminer from Wisconsin Master Gardener Program.  Wisconsin also has problems with leafminers in agricultural crops—corn blotch leafminer, vegetables, and alfalfa.  For mature ornamental plants the leafminers' effects are mostly cosmetic and don't usually severely damage them.  They can survive considerable leaf loss, but it may affect their vigor and make them more susceptible to other insects or disease.  Here is an article on controlling leafminers from Planet Natural and one on controlling birch leafminers from the University of Minnesota Extension Service.

By the way, our tree expert said that your cut tree could possibly, given the rainfall you receive, resprout from the roots (if your husband didn't dig them up) and grow up to be perfectly fine.




More Pests Questions

Tiny beetles eating a native plant in Austin, TX.
April 15, 2014 - Help! Found plant devoured in my wildflower garden! Covered with literally thousand of small black bronze beetles. They are on other plants but the other plants (native poppies, coneflower, coreops...
view the full question and answer

Moths around Sophora secundiflora from Driftwood TX
March 15, 2012 - Sophora secundiflora Our Mountain Laurel has a lot of large moths flying around it. Should we be concerned? Will they hurt the tree? thank you
view the full question and answer

Vehicle friendly oak trees for Austin
March 30, 2008 - Do Chinquapins, Shumards or Live Oaks produce lots of tree sap? I'm looking for a vehicle friendly Oak tree to be installed in parking areas in Austin, Texas.
view the full question and answer

Dealing with beetles feeding on cholla cactus
June 20, 2010 - Hi Mr. Smarty Pants, I bought a Cylindropuntia imbricata from the Wildflower center and it was growing like crazy. I recently noticed a lot of beetles feeding on it. Some are black and some are gra...
view the full question and answer

Mosquito problem from Mesa AZ
April 07, 2014 - We have a mosquito problem in our backyard, I think they're grass Mosquitos. I wanted to get lemongrass for a deterrent but both nurseries were out so I opted for rosemary. They're ALL OVER the rose...
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