大象传媒

In Central America, yucca plants and yucca moths are completely dependant on each other.

The tiny moths spend their days moving from flower to flower, inspecting them.

But not all the flowers are at the same stage of development since the stamens mature first, and it is these that the moth is looking for.

Once the female moth - who has already mated - has got herself some pollen, she gathers it into a tight ball which she holds under her head as she searches for other flowers that are at a different stage of development.

This time she is more interested in the ovaries at the centre of the flowers. She will then spend around 20 minutes using her egg-laying tube to lay her eggs in the base of the flower's ovary.

When she has finished she takes some grains of pollen from the balls she has collected and smears them into the stigma with mouth parts that have been specially developed for the purpose.

Then she will repeat the entire procedure in other ovaries of the flower. By pollinating the flower she ensures that her eggs will develop well in the ovary below and that, when they hatch into caterpillars, her young will have a rich source of food waiting for them in the form of seeds.

But there are more seeds than the caterpillars can possibly eat so when the yucca comes into fruit there are plenty of undamaged seeds to ensure that new plants will appear.

It is a very fine balance. Without the moth's special mouthparts, the yucca would not be pollinated. And without the yucca, the moth's caterpillars would starve.

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