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Desert Diary
Plants/Yucca Moth Strategies


Yuccas and yucca moths have a mutualistic relationship. The yucca needs the moth for pollination, and the moth needs yucca seeds as food for its young. So strong is the tie that likely both a yucca and its particular species of pollinator will become extinct if either falters.

Life is not without problems, however. In dry years, yuccas may not be able to produce seeds. This isn't a serious difficulty for the yucca, because it has more years to try for successful reproduction. For the short-lived moths, however, it's a potential disaster—in years with no yucca seeds, all their young would die. How can you guarantee there will be moths around the next year? Simple—mimic the strategies of desert annual plants, wherein only a portion of the seeds germinate each year.

During good years, the mature moth larvae drop from the yucca and burrow into the ground where they go into dormancy, called diapause. Some will metamorphose into moths and emerge the following year. Others will remain in diapause for 2 or more years, hopefully emerging to bountiful yuccas.
pen and ink

Listen to the Audio (mp3 format) as recorded by KTEP, Public Radio for the Southwest.


Contributor: Arthur H. Harris, Laboratory for Environmental Biology, University of Texas at El Paso.

Desert Diary is a joint production of the Centennial Museum and KTEP National Public Radio at the University of Texas at El Paso.

blossoms of Yucca torreyi

Half of the partnership. Torrey Yucca (Yucca torreyi) blossoms, University of Texas at El Paso campus. Photograph by A. H. Harris, 19 March 2001.



Aker, C. L. 1982. Spatial and Temporal Dispersion Patterns of Pollinators and Their Relationship to the Flowering Strategy of Yucca whipplei (Agavaceae). Oecologia 54:243-252.

Aker, C. L., and D. Udovic. 1981. Oviposition and Pollination Behavior of the Yucca Moth,Tegeticula maculata, (Lepidoptera: Prodoxidae) and its Relation to the Reproductive Biology of Yucca whipplei (Agavaceae). Oecologia 49:96-101.

Baker, G. H. 1986. Yuccas and Yucca Moths--A Historical Commentary. Annals of Missouri Botanical Garden, 73:556-564.

Johnson, R. 1988. The Reproductive Cost to the Yucca Plant (Yucca filamentosa L.) in its Mutualistic Relationship With the Yucca Moth (Tegeticula yuccasella Riley). Journal of Tennessee Academy of Science, 63:77-78.

Kingsolver, R. W. 1984. Population Biology of a Mutualistic Association: Yucca glauca and Tegeticula yuccasella. Ph.D. Dissertation, University of Kansas, Lawrence.

Miles, N. J. 1983. Variation and Host Specificity in the Yucca moth, Tegeticula yuccasella (Incurvariidae): a Morphometric Approach. Journal of Lepidopterists Society, 37:207-216.

Ramsay, M. A. 1994. Preliminary Investigations Into Aspects of the Population Biology of the Yucca Moth, Tegeticula yuccasella, and the Plant Yucca filamentosa. M.S. Thesis, Emporia State University, 35 pp.

Schrock, J. R., and G. Leisman. 1987. Wildflower in the Spotlight: Yucca or Soapweed, Yucca glauca. Kansas Wildflower Society Newsletter, 9(1):5-11.

Web Resources

Wayne's Word. Text and photographs of yuccas and yucca moths.