The Genista Caterpillar is the caterpillar commonly seen on the new growth of Texas Mountain Laurels. Note, it is ONLY the new growth that they will be found on. This saves us time and money in our control efforts.
Any time Texas Mountain Laurels have new growth emerging, as in the spring and fall, is a good time to protect the new growth by spraying it with either Bt (Bacillis thurengiensis) or Spinosad. These are both Organic solutions to control caterpillars.
NOTE: Spinosad is toxic to bees, and should NOT be sprayed on Texas Mountain Laurels while they are blooming. Bt is only toxic to caterpillars and is safe to spray when the trees are blooming.
I usually keep a “ready to spray” bottle of Captain Jack’s Deadbug Brew, Summit Caterpillar and Webworm Control or Fertilome Bt products next to my hose and spray every Sunday morning as a preventative. Remember, you only need to spray the new growth!
Another helpful control is to release beneficial insects, such as small, stingless Trichogramma Wasps, at the same time you spray the Bt. Bt will not harm the wasps, but will still control the caterpillars. (Do not use Spinosad if you are releasing the Wasps.) The Wasps come as eggs on strips of paper. You tear off a square of the paper and set it in the tree.
Because Texas Mountain Laurels produce their flower buds for next spring on this summer’s growth, it is especially important to protect the new growth of your trees. With a little effort, you will have a beautiful tree with many blooms next spring!