Some beetle species use "mirror-image" scent molecules, called pheromones, to find mates. One type of scent attracts males, while its exact opposite repels them. This helps beetles avoid mating with the wrong species.
Researchers have studied how the Japanese beetle (Popillia japonica) and another beetle, Anomala corpulenta, use these scent signals. The scent involved is known as japonilure.
How Beetles Use Scent to Find Partners
Different Forms, Different Signals: Japonilure comes in two forms, like a left and right glove. These are called R-japonilure and S-japonilure.
Attraction and Repulsion: For Popillia japonica, the R-form of japonilure attracts males, but the S-form makes them stay away.
The Opposite Effect: In contrast, for Anomala corpulenta, the S-form of japonilure attracts males, while the R-form causes them to avoid the scent.
Avoiding Mistakes: Scientists believe this difference helps different beetle species avoid mating with each other, even if they live in the same areas. This saves the beetles' energy for mating with their own kind.
Scientific Discovery and Collaboration
A team of researchers, including scientists from UC Davis and their colleagues in China, made these discoveries.
They identified a third beetle species that uses japonilure to attract males.
This work sheds light on how chirality (the property of having mirror-image forms) plays a role in insect communication.
Future Implications
Understanding these specific scent signals could help in:
Controlling Pests: Developing new ways to manage agricultural pests like the Japanese beetle.
Chemical Ecology: Learning more about how insects interact with their environment through scents.
