It is a common belief that going out at night is much more dangerous than going out during the day. Although reasons for fearing the dark differs amongst humans, the fear is usually rational and can often prevent unnecessary tragedies. As a teenager, I was often irked when my parents refused to let me out of the house to see my friends. I insisted that many of my friends are only free after a certain time at night because they were working or doing other things. Unfortunately, my parents maintained their position, and I never really understood why the night was always made out to be so treacherous.

Plants, on the other hand, need not fear the dark. They are immotile, so hazards such as driving or running in the dark are not an issue. They cannot see, so dangers of limited vision are also negated. For ages, tobacco plants seemed to embrace the dark by opening its flowers for pollination at night; after all, why fear the dark when you are a plant? However, it has recently been discovered that tobacco plants now open their flower buds in the morning and close them at night, and have seemingly adopted humans’ general fear of the dark. But why should a plant fear the dark?

This “fear” is due to predation of the plants by caterpillars. These caterpillars come from eggs of certain female moths that are only active at night. The moths, attracted to the aroma of the tobacco plants, will approach the flower and lay their eggs in it. When the eggs hatch, the young caterpillars feed relentlessly on the tobacco plant surround them. By opening the flower in the morning instead of in the night, the moths can no longer lay their eggs inside the plant. In addition, hummingbirds are able to pollinate the plant during the day without harming the plant. With these benefits in mind, it looks like fearing the dark might not be so bad after all.

Discussion Question: How do you think this will affect the tobacco plants and moths in the long run?
News Article: http://www.sciencedaily.com/releases/2010/01/100121135659.htm
Journal Article: http://www.sciencedirect.com/science?