Explore Plants

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
    
 

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

Sunday - April 14, 2013

From: Aledo, TX
Region: Southwest
Topic: Pests, Seeds and Seeding, Cacti and Succulents
Title: Black bugs on yucca from Aledo TX
Answered by: Barbara Medford

QUESTION:

We have flowering yuccas that have thousands of small black bugs that seem to be hurting the plant. They are not on any other foliage in our beds. What do I use to get rid of them??

ANSWER:

When we answer a question about a plant, we always like to have a more specific species for an example. There are 28 yuccas native to North America and 18 native to Texas. According to this USDA Plant Profile Map Yucca pallida (Pale-leaf yucca) is native to Parker County. That may not be the precise yucca you have, but the bugs on it would probably be the same for all members of the Yucca genus.

We believe you might be seeing the larvae of Tegeticula yuccasella or yucca moth. At the Lady Bird Johnson Wildflower Center, we frequently clean the seeds that have been gathered of native plants in Texas, including the yucca. Sometimes when we have young people volunteering for this, we get a certain amount of squealing when a little black worm emerges out of the center of a stack of yucca seeds in their pod. Those seeds have to be abandoned and not saved for our seed bank, because the depredations of the moth larvae have destroyed the usefulness of the seeds. Please read this article on Yucca and Yucca Moths from the Chihuahuan Desert Center. The yucca and the moth are interdependant so destroying the moth is not a good practice.

If, however, you feel that it is something else that is damaging your plant, read this article from Arizona Cooperative Extension on Problems and Pests of Agave, Cactus and Yucca.  You will have to scroll down to Page 6 to find the section on Insects. If some of these match what you are seeing, the article gives some management suggestions.

 

From the Image Gallery


Pale-leaf yucca
Yucca pallida

Pale-leaf yucca
Yucca pallida

Pale-leaf yucca
Yucca pallida

More Cacti and Succulents Questions

Removal of mature agaves
November 20, 2007 - Hello- we live in Austin, TX and have a bed of different varieties of agave. They are near the walkway to our house, and are so out of control they pose a hazard to our guests walking up to the house...
view the full question and answer

Plants to accompany cactus and agave
October 09, 2005 - What plants would look well with cactus and agave to soften the look of spikiness? Also, a homeowner in our association wants the association to plant a pyracantha at the corner of the street to preve...
view the full question and answer

Nightflowering plants native to Northern Illinois
October 12, 2010 - Looking for any/all info on night flowering plants that are native to Northern Illinois.
view the full question and answer

Sap from agave causing reactions from Edgewater FL
April 06, 2012 - Not only was I stuck with the century plant thorns and needle like ends when I was digging up its pups, but I also broke the carrot-like root of a few when I was transplanting and got the white sap on...
view the full question and answer

Plants for planting in gourds
March 15, 2009 - I enjoy painting dried gourds. This spring I got the idea to paint a gourd and cut holes in the side and plant some small blooming flowers. I have seen "hen and chickens" growing out of holes in the...
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.