The “Murder Hornet” has officially arrived in North America. Known for its deadly sting, ruthless  nature and appetite for the already imperilled honey bee, the world’s largest hornet lands on the continent with a heavy reputation, experts warning that the arrival of this 2-inch warrior could lead to a series of serious environmental implications.

Native to the east and southern regions of Asia, the invasive Asian giant hornet (Vespa mandarinia) presents itself as a highly-developed predator. These hornets are least active during the winter, when newly-mated queens enter a period of hibernation in preparation for the spring. Throughout the next summer and early fall, worker hornets will travel several miles to find food to sustain their colony.

Although they typically feed on a wide variety of insects ranging from wasps to beetles, there is one particular prey of the Asian giant hornet that has caught the world’s attention: honey bees. Presenting itself as a formidable predator, these hornets can use their large and powerful mandibles to wipe out an entire honey bee hive in just a matter of hours, leaving behind decapitated heads and flying away with mutilated thoraxes to feed their young.

In regions such as Japan, the term “murder hornet” has entered the vocabulary, where it has been known to kill as many as 50 people per year with its venomous and deadly sting. Because the stinger of the murder hornet always remains attached to its body, it is capable of stinging their victims multiple times, injecting a potent neurotoxin made up of eight different chemicals. 

Yet, the Asian giant hornet “is not really a human killer,” said Alex Olivera, from the Center for Biological Diversity. “They actually kill few people. The main threat of this giant hornet is that it is an invasive species that beats honey-producing bees.” 

In the Pacific Northwest, where the hornets have most recently been spotted, farmers rely on honey bee populations to pollinate essential crops such as apples and blueberries. Throughout the United States, the production of nearly 100 agricultural crops depends on bee pollination, with the most common contributor being the European honey bee (Apis mellifera).

Honey bees contribute over $20 billion to U.S. agriculture every year, and with the arrival of the murder hornet, both beekeeping and agricultural industries are on high alert. 

So why isn’t this hornet so much of a problem in other parts of the world? In Japan, where murder hornets are most commonly found, Japanese honey bees (Apis cerana japonica) have co-evolved with the hornets to protect themselves against these fierce killers. By attacking in large numbers, Japanese honey bees are able to ambush and swarm these hornets, effectively suffocating them to death under extremely high temperatures and high levels of carbon dioxide. 

However, western counterparts of the Japanese honey bee lack any sort of innate defense against the hornet, leaving them and their colonies vulnerable to destruction. This includes the European honey bee that was introduced to North America in the early 1600s, which still stands today as one of the most important, if not the most important, pollinators in the agricultural sphere. 

But the threat posed by murder hornets isn’t just limited to agriculture and food supply chains. From an ecological standpoint, the introduction of the invasive hornet has serious implications for the loss of biodiversity, says Olivera. “The introduction of invasive alien species is the second cause of loss of biodiversity on the planet, and the Asian giant hornet is a prime example of this.”

Notwithstanding, and despite recent headlines, American honey bees still have many other, larger issues to be concerned about: “Both wild bee populations and managed honey bees face a slew of diseases and pests, land-use change, habitat loss, exposure to pesticides and other agrochemicals,” said James Crall, a postdoctoral fellow in the Department of Organismic and Evolutionary Biology at Harvard University. All of these factors combined have serious potential to exacerbate the impacts on not just honey bee populations, but also their role in supporting biodiversity within their ecosystems. 

According to a year-long study conducted by the Bee Informed Partnership and the University of Maryland, between April 2019 and 2020, beekeepers in the U.S. reported an estimated 43.7% loss in honey bee colonies, the second highest annual loss rate since 2010. These numbers alone are enough to alarm researchers of the continuous ecological threats American honey bees face as their numbers continue to decline at record-high rates. 

Even with the introduction of the murder hornet, experts like Crall say that it still remains uncertain as to whether these hornets will become a permanent addition to North America. 

“At this point it’s really important to be monitoring — as is happening in Washington State — but I wouldn’t say they pose an imminent threat to bees,” said Crall. “I think the giant hornet ranks well below all of these in terms of what keeps me up at night.”

Adding another stressor to the vital and already declining American honey bee population may lead to another ecological catastrophe. That is why it is crucial that steps are taken to effectively contain the murder hornet’s arrival before it becomes too widespread. 

The State Department of Agriculture in Washington has already begun setting up roughly 600 traps in an effort to catch the invasive hornet. With more monitoring, targeted traps, and a bit of luck, officials hope that they will be able to take out the hornet for good.

For The Yucatan Times
Zachary Huang-Ogata

Zachary Huang-Ogata is a freelance writer specializing in science and the environment.