Today my hip and knees
hurt, but I tottered around outside anyway. I couldn’t resist the 72ยบ F.
temperature and semi-sunny sky. I made my way slowly and carefully, which gave
me plenty of opportunity for noticing details. I was making a mental list of spring
clean up chores, one of which is to cut the yucca bloom stalks from last year.
Yucca plants were in the
yard when we bought this place almost 39 years ago. They are still here.
We made the mistake of
cutting the seed stalks and tossing the over the fence into the pasture. Now
yucca colonies are appearing all over the pasture. They make a beautiful
spectacle when they bloom each June, tall sentinels adorned with white
blossoms.
There’s no telling how many
yucca plants we would have if not for nature’s yucca population control method.
The yucca blossoms attract yucca moths, which lay their eggs in yucca
blossoms. The larva then feed on some but not all of the developing yucca seeds
and exit the seedpod by boring tiny holes in the hardened casing. Here you can
see two exit holes used by larvae as they emerged.
But that isn’t the whole
story. Not only does the yucca moth depend exclusively on the yucca flower for
its continued existence, the yucca moth is the yucca’s only pollinator. This
symbiotic relationship has enable both species to survive through many
millennia. But, if the yucca moth larvae didn’t eat seeds we would be overrun
by yucca plants.
Human beings also have
symbiotic relationships with various other life forms, but we have conquered
many other life forms that would control our population. As more and more
diseases and health conditions are conquered, we have reached the point where
only war and famine can keep us from totally covering and possibly destroying
the earth.
To learn more about the
relationship between the yucca plant and the yucca moth, visit http://prairieecologist.com/2010/12/08/the-yucca-and-its-moth/.
Copyright
2014 by Shirley Domer
