The New Student's Reference Work/Yucca Moth

Yucca (yŭk' k&#0550;) Moth, a small moth which gathers pollen and fertilizes the yucca-plant. A very remarkable relation has been shown to exist between this moth and the plant. The yuccas are lily-like plants, of which the Spanish bayonet is an example. The stamens are so placed that the pollen cannot get into the tube of the stigma without artificial aid. The plant is sterile without the moth, and the larvæ of the latter feeds on the seeds, so that, in fertilizing the plant, the mother moth is providing for her offspring. The female moth (Pronuba yuccasella) is about half an inch long and of silvery white color. She begins her operations after dark, and, in setting about to provide for the future generation, she first collects a pellet of pollen with her jaws and fore legs. She then begins to deposit eggs in the walls of the unripe fruit-pod, using her lance-like ovipositor to penetrate the outer covering. She then goes to the tube of the stigma, which leads into the fruit-pod and thrusts pollen down it, using her tongue to push the pollen toward the undeveloped seeds. The larvæ are hatched and feed upon the developing seeds, but as not all of these are consumed, the double purpose has been effected of fertilizing the plant and providing food for her young. Consult The Yucca Moth and Yucca Pollination, Missouri Botanical Garden Report for 1892.