Host an Event Volunteer Join Tickets

Support the plant database you love!

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

Please forgive us, but Mr. Smarty Plants has been overwhelmed by a flood of mail and must take a break for awhile to catch up. We hope to be accepting new questions again soon. Thank you!

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 Pests Questions

Can tulip tree sap be used to make syrup in Bunker Hill IN?
July 10, 2009 - I was just wondering if tulip tree sap could be used to make syrup. I saw the sticky stuff on the leaves and decided to taste test it and it was very sweet, unfortunately I later found out that I was ...
view the full question and answer

Problems with Live Oak in Boerne TX
April 24, 2011 - I had my large Live Oak trimmed last year. This spring there seems to be a problem with leaf growth. Most leaves are small in nature and appear to have been attacked possibly by bugs. Many of the bran...
view the full question and answer

Control of grasshoppers from Goldthwaite TX
July 07, 2012 - How long do grasshoppers live. They are eating our flowers, plants and trees.
view the full question and answer

Varmints disturbing plants in NH
August 04, 2011 - I planted herbs and perennials, then put paper down and bark. At first an animal just disturbed the paper around the plants, exposing it. Today two plants are dug up and are completely gone. No sig...
view the full question and answer

Non-native Chamaecyparis pisiflora turning brown in Fuqua-Varina NC
December 10, 2012 - I have a "Soft Serve False Cypress" Chamaecyparis pisifera'Dow Whiting PPAF, that has only been in the ground for 6-7 months. I just noticed that the branches and leaves are starting to die, turni...
view the full question and answer

Support the Wildflower Center by Donating Online or Becoming a Member today.