In 2019, Asian giant hornets — better known to the public as murder hornets — first appeared in the United States while the Washington State Department of Agriculture located and exterminated three of the invasive species' nests in 2021 in the hopes of eradicating them, there's still some concern that the hornets could still be out there. Now, however, researchers may have found a new way to combat them. According to a new study published in the journal Current Biology, male giant hornets can be lured into traps using sex pheromones.
At the University of California San Diego, a team led by professor and associate dean in the school's department of biological sciences James Nieh created a series of traps that used sex pheromones to attract the male hornets. Per the study, researchers used a mixture of synthetic pheromones along with a natural sex pheromone from a female giant hornet and tested them near hornet colonies in China's Yunnan province. The study found that the synthetic pheromone — paired with a dummy female hornet — was more than 16 times more effective than traps without pheromones. Per the study, scientists captured thousands of hornets in a single day using the traps.
However, while the traps do work, there are some limitations. The traps only work on male hornets and, but female hornets could still form colonies if they've already been mated, something that Allen Gibbs, professor in the department of life sciences at the University of Nevada, Las Vegas told CNN. Gibbs was not involved in the study.
"This method attracts males, but if they've already mated, the females are free to fly off and start a new colony," he said. Gibbs also noted that murder hornets only mate for a very limited window of time in the fall making the trap system time sensitive.
Thus far, it's unknown if more murder hornets will be found in the United States in 2022. Washington state officials are hopeful that the work done in 2021 to locate and destroy their nests will have eradicated the hornets here, though scientists won't know for sure for several months. The previous nests were discovered in the fall of the year — in August in September in 2021 and near the end of October in 2020. Thus far, all of the nests have been found in one area east of Blaine, Washington and officials are hopeful that the insects haven't spread, though they do ask people continue to keep an eye out and report what they see.
"We have found that people, just keeping their eyes open and reporting sightings to us, you know, getting a photo of what they're seeing and sending that into us, that is actually more effective than our trapping," Karla Salp, public engagement specialist for WSDA told Portland's KOIN.
What do you think about the latest development in stopping murder hornets? Let us know your thoughts in the comment section!