However, when goldenrod plants in the wild had been exposed to male fruit fly's amorous odor, the plants tended to harbor fewer egg-laying sites. What's more the plants also became more resistant to attacks by other insects.
The exact physiological means by which the plants smell the flies is still a mystery.
"Our understanding of plant olfaction in general remains quite limited," said Mark Mescher, an entomologist at Penn State, in a press release.
"It's become increasingly clear in recent years that plants are responsive to odors," said Mescher. "But previous examples of this are all plant-to-plant. For example, some plants have been shown to respond to the odor of insect-damaged neighbors by priming their own defenses. What's new about this is that it seems that plants may sometimes be able to smell the insects themselves."
The study was published in the Proceedings of the National Academy of Sciences.
Goldenrod, Solidago sp. (Liz West, Wikimedia Commons)