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?

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
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

Eliminating yuccas from yard in Woodinville, WA
August 21, 2008 - My plant areas are being overrun by Yucca plants. They are also growing and destroying my asphalt driveway. How can I get rid of some of them permanently?
view the full question and answer

Projected longevity of Opuntia fragilis (Fragile Prickly Pear)
November 25, 2005 - How long does Opuntia fragilis live? Thank you.
view the full question and answer

Unidentified stalk, possibly manfreda, from San Marcos TX
May 23, 2014 - I had a very weird stalk pop up in my yard in San Marcos TX this month (May 2014) It bloomed very quickly and appears to be a manfreda but there is no rosette, or leaves of any kind - just the thick o...
view the full question and answer

Need advice about an agave that didn't survive the winter in Myrtle Beach, NC.
March 09, 2011 - I live in Myrtle Beach, S.C. bought an agave big last summer and it died in the winter. Some green is showing on the bottom should I cut it all down because the whole top is dead. Thank you
view the full question and answer

Blue agave with freeze damage in Lockhart TX
March 16, 2011 - I recently planted a blue agave plant, and 4 days after I planted it the temperature dropped to 20 degrees at night. The plants are still alive but 75% of the outer limbs turned brown. What do I do wi...
view the full question and answer

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