What’s new: Researchers recently found a way to manage and reduce the population of the Japanese giant hornet famously nicknamed the “Murder Hornets” through the use of pheromone traps to lure in male hornets.
Why it matters: Being able to manage the population of murder hornets by reducing the amount of breeding would mean less hornets for humans to worry about and less people killed. A smaller population also equals a smaller chance of them becoming a harmful invasive species outside of Asia.
What they’re saying: While the giant hornets are native to East Asia, they have recently been discovered in North America in British Columbia, Canada, and in Washington, USA. They are an invasive species.
Japanese giant hornets are the largest species of wasp in the world. They’re 6 millimeter stingers that can inject venom so powerful that multiple stings can be lethal to humans. In Japan, they sometimes kill up to 30 people a year. The majority of deaths occur as a result of anaphylactic shock or multiple organ failure after being stung multiple times.
Researchers studying a colony of giant hornets in Yunnan, China were able to identify and isolate compounds in the female sex pheramones secreted from giant hornet queens. The identified compounds include caproic acid, which has an “oily, cheesy and urany” odor, decanoic acid, and octanoic acid, which has a pungent odor sometimes found in animal milk and in artificial fruit flavoring.
Using these compounds, entomologist James Nieh of UC San Diego developed a “pheromone trap” that successfully lured in thousands of male giant hornets.
The isolated compounds in the pheromone trap only lure in male giant hornets. No other insects, species of wasp, or even female giant hornets were affected by the trap meaning pheromone traps have little to no ecological impact.
What’s next: Implementation of the pheromone traps in BC, Canada and Washington state where the species is invasive will begin after Nieh and his team continue testing in China.
The research team’s goal is to identify more compounds found in the sex pheramones of female giant hornets so they can more effectively mimic and reproduce odors closer to actual hornet pheramones.
The team will also set out to determine the effective range of the pheromone traps so that in the future their potential as pest management devices can be optimized.
The big picture: Managing murder hornet populations will have a massive impact not only on reducing the yearly death toll but also on the ecosystems they are used in, particularly those in which the giant hornet is an invasive species.
While the hornets caused a commotion in early 2020 in the media as they can kill humans, they also pose a huge threat to the honeybee population as they kill and feed honeybees to their larvae.
Preserving honeybee populations is critical as they are crucial pollinators in various ecosystems across the globe.
In the near future we will likely be able to implement pheromone traps in highly populated areas across Asia as well as throughout the Pacific Northwest in North America to stop their invasion.
Kevin Murasaki grew up moving back and forth between Chicago and Yokohama, Japan. Known as a "hafu", Kevin is half Japanese, and half American. Now a videographer and drone operator based in Fukuoka, Japan, Kevin enjoys playing basketball, driving on mountain or "touge" roads, and fishing in his free time. Kevin is a recent graduate of the University of British Columbia.