Manage Genista Caterpillars To Keep Your Mountain Laurels Looking Their Best

Our Texas insect expert answers common questions about bugs.

By Laura RiceApril 24, 2018 11:47 am,

Wizzie Brown, an insect specialist with the Texas A&M Agrilife Extension Office, says genista caterpillars are easy to spot on your blooming Texas mountain laurel plants.

“They’re going to be usually a yellowish but sometimes a yellowish green,” she says. “They have black and white dots on their body, and they have these little spiky hairs that come off. Even though they have the spiky hairs, they are not going to try and sting you, so you can touch them.”

Brown says the caterpillars will cover part of the mountain laurel with a loose webbing.

“It’s not as thick as a fall webworm,” she says. “A lot of people confuse them for fall webworms because they do create webbing and they’re yellow and green. So they’re kind of similar.”

The caterpillars don’t damage the plant, but sometimes they’re a nuisance.

“It makes it look ratty and people don’t like that,” Brown says. “So, it’s not like they’re a huge pest, but a lot of people do feel like they need to manage them. So if you are one of the people that want to manage them, then you do have the option of handpicking them, depending on how many you have and how large your mountain laurel is. If you have a larger one, then you can use pesticides.”

In that case, Brown recommends a couple ideas.

“They have naturally derived things, the Bacillus thuringiensis – it’s also known as BT and you want to get the variety that is kurstaki,” she says. “That only targets caterpillars, so it’s not going to kill any other groups of insects other than caterpillars. Another one that is a less toxic product is spinosad.”

Brown says genista caterpillars won’t damage the mountain laurel.

“They’re actually great to feed birds, and lizards, and other insects that feed on caterpillars,” she says. “So even if you don’t do anything, they’re not going to take over the world.”


Written by Angela Bonilla.