They’re here. Native to East Asia, the so-called murder hornets were spotted in North America for the first time late last year and just again in May. The presence of the predators, which can grow as much as 2 inches in length, drew media attention because their frightening prowess at killing honeybees means they could adversely affect the supply of foods we consume that require pollination. Known officially as the Asian giant hornet, the species is capable of wiping out an entire hive in a matter of hours, decapitating bees with powerful mandibles and hauling away the thoraxes to feed their young. The hornets are less of a direct threat to humans, although they do kill about 50 people a year in Japan, where they are most prevalent. The Gazette spoke with Benjamin de Bivort, the Thomas D. Cabot Associate Professor of Organismic and Evolutionary Biology at the Faculty of Arts and Sciences, and James Crall, a postdoctoral fellow working in de Bivort’s lab. Both researchers study pollinators, like bees, and they shared their views on how much we should worry about the sightings in Washington state and British Columbia.
Benjamin de Bivort and James Crall
GAZETTE: Remind us, why should we care about what happens to honeybees?
CRALL: Bees are incredibly important for human well-being, including both managed honeybees and wild bees. Put simply: About one in three bites of food comes from crops that depend on animals for pollination, and bees are the most important group of pollinators. The parts of our diet that depend on pollinators — including many fruits, nuts, and vegetables — are really nutritious. Losing pollinators means less healthy food and worse health outcomes for humans. Of course, beyond their role in food production, bees are incredibly important for preserving biodiversity, more generally.
DE BIVORT: From a basic science perspective, honeybees are particularly interesting because they live in societies of tens of thousands of individuals. This high level of sociality offers advantages and challenges for them as a species. For example, they have evolved an extreme form of division of labor and behave in ways that are highly altruistic. At the same time, each individual honeybee is highly dependent on her sisters, so when the colony as a whole is unwell, it is very bad news for all the individual bees.
GAZETTE: What were your initial reactions on hearing about the emergence of the Asian giant hornet here?
CRALL: My first reaction was that I’m really glad entomologists in Washington state have been so proactive in setting a monitoring system to look for these hornets. My second thought, though, was that I wish people reacted this strongly to all the other threats that we know full well are wreaking havoc on bee populations, like climate change, and many aspects of industrialized agriculture, including pesticides.
DE BIVORT: Yes, much depends on whether the wasps actually become established, meaning they reproduce to a stable, self-sustaining population size. I believe it’s rarely the case that an invasive species becomes established but is later eliminated through deliberate control measures. But if they do become established, then the honeybees will experience strong evolutionary pressures over the next years as they adapt to this new ecological interaction.