The world’s largest horn, the Asian giant horn (Vespa Mandarinia) Is popularly known as the “horn of murder”. Credit: Washington State Department of Agriculture
Honeybees spread animal buttermilk at the entrance to their hive to effectively cut off huge hornets.
What is the best way to ward off giant hornets if you are a hive? Animal dung for the first time, according to a study by the University of Guelph.
U.S. researchers have collected and applied animal manure spots around the hive entrance to prevent a raid on a beehive by an Asian horn in Vietnam.Vespa Tire) Whose North American cousins have been called “murder hornets.”
This discovery is also the first to document the use of tools by bees.
An invasive species of North American native to Asia, giant hornets are as long as golf tea and can contain up to seven times as much venom in a single bite in an ordinary can.
Murder Hornet (V. manderinia) was discovered in 2019 in British Columbia and Washington. The arrival of the toxin in North America poses a threat to human safety as well as to local bees and ecosystems.
Prof. Guard Otis of the U.S., who has studied bees in Vietnam for decades, said the Hornets could eventually raid similar beehives in North America.
“The Giant Hornet is the biggest wasp that threatens bees. They are their most significant predators, ”said the professor of environmental science.
Otis did the study with lead author Heather Matilla, who completed her PhD at Guelph University in 2006 and is now a professor of biology at Wellesley College in Massachusetts. Other co-authors were G-Grad students Hannh Pham and Olivia Knight, as well as former U.S. students Nogok Pham and Lian Nugian of Vietnam.
Recently published in the journal Plaza one, The study was conducted in Vietnam, where Una G researchers conducted the study V Soror.
Honey bee is taking dung in her mouth. Credit: Heather Matilla
Otis said these two species are the only hornets that recruit structures in an organized attack that could lead to structure breakage, Otis said. Hornets raid nests, kill bees and take away larvae and papayas so they can feed on their own growth.
Researchers have discovered that bees have developed pre-rescue defenses by collecting animal dung and placing them at the hive entrance.
“This study shows a significant symptom that these bees have to defend themselves against really terrifying predators.”
He said that unlike his Asian counterparts, bees in Canada lack similar protection. This means that North American beekeepers will have to rely on destroying Hornets structures, or hope that weather or other factors will limit the spread of Hornets.
Referring to the Apis melifera, a species of bee commonly found in Canada, Matila said, “They have not had the opportunity to develop a defense. It’s like going into the cold of war. ”
Otis launched the project after asking Vietnamese beekeepers about the dark spots at the Asian bee hive entrance. Funded by the Government of Canada as part of a successful beekeeping development project, he conducted workshops in rural villages with high levels of poverty from 2007 to 2011.
During an interview, an experienced beekeeper explained that the substance was buffalo dung. The beekeepers Otis has worked with have linked these hive locations to the Hornet. “Dung collection is a behavior that has never been reported for bees before, and no one has studied the phenomenon.”
In 2013, the U.S. team received 25 25,000 from the National Geographic Society for the study.
Giant Hornet at the entrance to the hive without dung. Credit: Heather Matilla
The researchers collected dung from aquatic buffaloes, chickens, pigs and cows and placed it on a mound near the hive. By the end of the day, about 150 bees had visited the hive, collecting more fragrant manure, especially pork and chicken.
The team marked individual bees to identify them on their hive. Minutes later, they recorded videos of marked bees applying material to the entrance to the structure.
Hornets spent less than half the time at the entrance to the structure with heavy dung spots through, as they spent only one-tenth chewing at the bee hive entrance to get to the bee hives. They were also less likely to carry out mass attacks on hives with heavier spots.
Researchers are unaware of what prevents hornets, although they suspect the insects are repelled by the smell of dung. Dung can also mask the odor emitted by bees.
To better understand Hornet’s behavior, the researchers racked up a chemical pheromone applied by Hornet while marking their target hive. When the pheromone is applied to the bee’s entrance, it asks the hive to apply dung to the hive.
Many scientists disagree on whether certain animals are – let alone insects – use tools.
To qualify as tool users, animals must meet certain criteria, including the use of a substance from the environment – in this case, dung. The bees clearly use the material to replace the hive with purpose, Otis said. And they shape and mold it from parts of his mouth, which he said meets the test of holding or manipulating a tool.
Vietnamese beekeepers usually control the hornets by standing guard and sweating individuals, preventing them from escalating their attacks.
“If you allow them, a group of Hornets will gather, attack the colony and take over. Beekeepers control them by moving between their hives and blowing hornets every day. “
Otis said he was already nervous about working near the giant Hornets. Hazmat suits worn by researchers in Japan for safety are impractical in the Vietnamese heat, he added. Within a few days, the team learned that the Hornets were not defensive when they were in the bees and away from their own structure.
“I drowned by one and it was the most terrible bite of my life.”
Ref: 9 December 2020, Plaza one.
DOI: 10.1371 / journal.pon.0242668
