The relationships between plants and insects are often intricate and complex. One such relationship is that between the yucca plant and the yucca moth. Just as the honeybee and the flowers it pollinates need each other, so do the yucca and the yucca moth.
Female yucca moths have a few days to deposit approximately one hundred eggs. So they fly around, scattering their eggs onto various yucca flowers. A female typically injects about three to five eggs into one yucca flower’s ovary. In the process, she benefits the flower by pollinating it.
Here’s where this relationship gets more complicated though. When the moth’s larvae hatch they feed on about twenty of the yucca flower’s three hundred seeds. However, if too many larvae hatch inside one flower, the plant will abort the flower and the larvae will die. Therefore, it’s to the advantage of the moths to be sure the flowers they deposit their eggs in do not become overloaded with eggs. Thus, the moths have developed communication through scent.
When a female moth lands onto a flower, she uses her antennae to inspect the flower for the scents of previous female visitors. If one or more moths have already deposited eggs in that flower, this visitor will either reduce the number of eggs she lays or move onto another flower. When she does decide to lay her eggs onto a particular flower, she drags her abdomen about the surface of the flower in order to leave her own scent as a warning to future visitors.