Mirror Image Pheromones Help Beetles Swipe Right

New research shows how Japanese scarab beetles use mirror-image pheromones to find mates and avoid interbreeding.

Published on Feb. 23, 2026

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New work from U.S. and Chinese scientists shows how Japanese scarab beetles use mirror-image pheromones to find mates. The research could lead to better monitoring and control of these significant agricultural pests.

Why it matters

The discovery of how these beetles use pheromones to communicate and avoid interbreeding could provide new tools for monitoring and controlling invasive beetle populations that damage crops.

The details

The researchers found that different beetle species, including the Japanese beetle, Anomala osakana, and the copper green chafer, Anomala corpulenta, all use mirror-image pheromones to attract mates. One form of the pheromone attracts males, while the other form repels them, preventing interbreeding between the species.

  • The original discovery of the pheromone japonilure attracting Japanese beetles was made in 1977.
  • Twenty years later, in 1997, Walter Leal discovered that a different beetle species, Anomala osakana, uses japonilure but with the opposite effect.

The players

Walter Leal

Professor of molecular and cellular biology at the University of California, Davis, and senior author on the new paper.

Popillia japonica

The Japanese beetle, a major agricultural pest that cannot be legally imported into the United States.

Anomala osakana

A closely related scarab beetle that uses japonilure as a sex pheromone, but with the opposite effect compared to the Japanese beetle.

Anomala corpulenta

The copper green chafer, another agricultural pest prevalent in southeast Asia and China that uses japonilure as a mating attractant.

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What they’re saying

“This prevents them from wasting time and resources.”

— Walter Leal, Professor of molecular and cellular biology (Proceedings of the National Academy of Sciences)

“The big goal is to use pheromones as tools to monitor and control populations of invasive beetles.”

— Walter Leal, Professor of molecular and cellular biology (Proceedings of the National Academy of Sciences)

What’s next

The researchers plan to further investigate how the beetles' pheromone receptor genes work, with the goal of developing new methods to monitor and control these agricultural pests.

The takeaway

Understanding how these beetles use mirror-image pheromones to communicate and avoid interbreeding could provide new tools for managing invasive beetle populations that damage crops and threaten food security.