Host an Event Volunteer Join Tickets

Your gift keeps resources like this database thriving!

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

Friday - June 11, 2010

From: Wilmington, NC
Region: Southeast
Topic: Pollinators, Pests, Cacti and Succulents
Title: Flying insects attacking yucca flacida in Wilmington NC
Answered by: Barbara Medford

QUESTION:

How do I treat flying insects from eating the flowers on my Yucca Flaccida shrub.

ANSWER:

Instead of being visited by damaging flying insects on your Yucca flaccida (weak-leaf yucca), we believe the flowers are being pollinated by the yucca moth partnered by genetics with that precise yucca plant. Here is a very good article from the  USDA Forest Service on Yucca moths. According to this article, at some point in the history of the moth-yucca co-dependence, the moth may have actually been feeding on the blooms.

When you see flying insects around your yucca, they are most likely females selecting a place to deposit their eggs, which is in the seed pod. She collects pollen and then pollinates the flower. When the larvae hatch, they feed on the seeds in the fruit. The mature yucca moth eats nothing, because they have only a few days to live. Please don't spray any pesticides around that yucca, because you will interrupt a very important process in your yucca. After the blooms have all gone and the fruit has dried, the fruit will open and the seeds will be ready to move to a place to grow a new plant.

Working  at the Lady Bird Johnson Wildflower Center on cleaning Texas native plant seeds to send to the Millennium Seed Bank, we have cleaned the dried fruits of yuccas to obtain seeds for the Seed Bank. Many of these seeds had little round holes in them, rendering them sterile, of course. This was the results of the larvae feeding; in fact, we sometimes chanced on a larva that had not yet left the nest. The yucca has adjusted to not allow all its seeds to be eaten by producing a LOT of seeds. Here are some pictures of the yucca moth.

Pictures of the yucca moth from Google 

Pictures of Yucca flaccida (weak-leaf yucca) from Google

 

More Cacti and Succulents Questions

Film growing on prickly pear from Austin
September 28, 2012 - We've just xeriscaped our front & back yards. Two of the spineless prickly pear cacti have a beige film growing on the paddles. The film is now moving further up the cactus, and one of the upper pad...
view the full question and answer

Sunny and shady lawns from Austin
April 28, 2012 - My front yard has a large bed surrounded by a mix of St. Augustine and Bermuda grass. Last summers heat killed off about 90% of the St. Augustine, which we would like to replace anyway to conserve re...
view the full question and answer

Trimming damaged leaves on agaves
February 05, 2009 - Some of the leaves on my agaves are damaged. Can I cut them off? If yes, how can I prevent the wound from becoming infected? Thanks.
view the full question and answer

Seeds of agave attenuata from San Diego CA
April 16, 2012 - After the agave attenuata bloom dried up there are seeds like thing hanging on the foxtail; do I leave it until it dies or do I chop that down. Are those seeds for propagation. The leaves of the plan...
view the full question and answer

Propagation of an agave from Dripping Springs TX
April 30, 2014 - Hi there, I have a Century Agave in my backyard. It is over 6 feet tall and is now producing the center stalk. I understand that means the plant is going to die. My question is how to harvest the pups...
view the full question and answer

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