Good Buddies: Symbiotic Relationships This neither harms nor benefits the whales = (commensalism). Yucca flowers are pollinated by yucca moths. research to find examples of symbiotic relationships in agriculture. Students will write Mutualism —plant and animal (yucca plant and yucca moth: each needs. Worksheet & cards developed for use with the Good Buddies activity available from Project Commensalism Yucca flowers are pollinated by yucca moths.
When a female is ready to lay eggs, she first goes to a yucca flower to collect pollen. Unlike most moth species, yucca moths have two short tentacles near their mouth that they use to scrape pollen from the anthers of the flower. As she collects the sticky pollen, the yucca moth packs it into a ball and sticks it under her head.
She then flies off to another yucca flower. When she arrives at the second yucca flower, usually one that has very recently opened, she goes straight to the bottom to find the ovary. She opens a small hole in the ovary and lays her eggs inside.
Once the eggs are laid, she scrapes a small amount of pollen from her sticky ball with her tentacles, walks to the stigma of the flower, and packs the pollen into tiny depressions within the style.
She may then return to the ovary of the same flower to lay more eggs or fly to another flower. Either way, before she leaves the flower, she marks it with a pheromone a chemical other moths can sense. This helps moderate the number of larva that hatch within each flower, and prevents the plant from aborting the flower altogether, which it will do if too many eggs are laid. Then she leaves in search of another inflorescence, not just another flower in the same bunch but in a different plant altogether, assuring in this manner the cross pollination of the yucca.
When she arrives at a new plant, she inspects the flowers and chooses the ones that are at the right stage. She can detect the smell of other female moths with her antennae and, if another one has been there already, she searches for another flower. This is good for the plant and for the future babies because, if too many eggs were laid in one flower ovary, the flower would abort and the larvae would starve.
The Yucca and its Moth
She lays her eggs in the ovary, no more than a handful; once again, if she laid too many eggs, the flower would abort. Afterwards she goes to the stigma of the flower and carefully removes some pollen from under her chin and deposits it on the stigma. Now the flower will produce a fruit and enough seeds to feed the larvae as well as ensure the reproduction of the plant.
In a few weeks, the larva is fully-grown. It drops to the ground; it buries itself and makes a cocoon. It will stay underground until the next spring.
However, some pupae remain dormant for more than a year. If the yucca fails to bloom one year because of weather conditions, there will still be yucca moths around. Yuccas are used as ornamentals well beyond their original geographic range.
The Yucca and its Moth | The Prairie Ecologist
The yucca moths have managed to follow the yucca and have enlarged their range east and north as far as the east coast and Alberta and Ontario in Canada.
For Additional Information Pellmyr, Olle.
The yucca moth family. The Natural History of Pollination. Timber Press, Portland, OR.