Bentley serves as the director of training and education for the National Pest Management Association (NPMA), headquartered in Fairfax, Va., and hosts NPMA's BugBytes. Kimsey, a global authority on wasps, bees and other insects, is a two-term past president of the International Society of Hymenopterists.
Kimsey fielded questions on the history of the hornet, its biology, its range, its behavior, its stings, and the news media frenzy over two reported incidents in North America. A single colony of the Asian giant hornet (AGH), Vespa mandarinia, was found and destroyed Sept. 18, 2019 in Nanaimo, Vancouver Island, Canada, and a single dead hornet was found Dec. 8, 2019 in nearby Blaine, Wash.
Concerned beekeepers worried that the hornets could become established and decimate their hives. Citizens throughout the country began reporting scores of "murder hornets," which turned out to be yellow jackets, European paper wasps, hover flies, hoverflies, moths and even a Jerusalem cricket (potato bug).
In the podcast, Kimsey relates that the Asian giant hornets are native to Asia, where the residents tolerate them. The beekeeping industry in Washington state, however, was "convinced that they are killing our honey bees," Kimsey told Bentley. "There's no basis in reality as far as I can tell," she said.
The Asian giant hornet is "one of about a dozen or so species in this genus," Kimsey said. She described them as "comically large and menacing looking."
The specimens in the Bohart Museum of Entomology are about 1.5 inches long. "I've never seen one two inches long. But it's a big animal--no question about it."
Bentley also discussed entomologist Justin Schmidt's Sting Pain Index, which rates the painful stings of some 83 hymenopteran species.
Kimsey agreed that the Asian giant hornet "can deliver a lot of venom" and "can sting repeatedly." But in her opinion, "the honey bee sting is the worst."
Other points Kimsey brought out included:
- The Asian giant hornets probably arrived here in cargo ships
- The larvae and pupae are restaurant-fare in some parts of Asia and are quite the delicacy
- The coronavirus pandemic has resulted in fewer cargo ships arriving in the United States from Asia, and thus fewer opportunities for hitchhikers.
Related Links (Bug Squad blog)
- About Those Asian Hornets (May 4, 2020)
- The Hornet Wars: 'A Bloody Dumpster Fire" (May 5, 2020)
- How Do You Say Murder Hornets? Delicious (May 8, 2020)
Matan Shelomi, former graduate student of Lynn Kimsey's and now an assistant professor of entomology at the National Taiwan University in Taipei, Taiwan, enjoys them.
- Incredible Work, and Timely, on 22 Species of Hornets (May 12, 2020)
The article, “The Diversity of Hornets in the Genus Vespa (Hymenoptera: Vespidae; Vespinae); Their Importance and Interceptions in the United States,” is the work of three entomologists: lead author Allan Smith-Pardo, U.S. Department of Agriculture Animal and Plant Health Inspection Service (APHIS); and co-authors James Carpenter of the American Museum of Natural History's Division of Invertebrate Zoology, and Lynn Kimsey, director of the Bohart Museum of Entomology and professor of entomology at UC Davis.
North America's first known colony of the Asian giant hornet, Vespa mandarinia, was detected and destroyed in September 2019 on Vancouver Island, British Columbia. A single V. mandarinia was found dead in Blaine, Wash., in December 2019.
“Hornet species identification can be sometimes difficult because of the amount of intraspecific color and size variation,” the authors wrote in their abstract. “This has resulted in many species-level synonyms, scattered literature, and taxonomic keys only useful for local populations. We present a key to the world species, information on each species, as well as those intercepted at United States ports of entry during the last decade.”
The journal article includes images of the 22 species and some previously described subspecies. The key should help state and federal officials identify the Vespa species, the authors said. Beekeepers, farmers and ecologists and others on the lookout for the Asian giant hornet can also benefit from the key.
In the USDA-funded research, the trio combed through scientific literature and museum collections to separate the species. They list their sources and offer insights on the distribution of each hornet, and a discussion.
The Asian giant hornet's distribution is India, Sri Lanka, Bhutan, Nepal, Myanmar, Thailand, Laos, Vietnam, Malaysia, Malaya, China, Hong Kong, Taiwan, eastern Russia, Korea, Japan (including Ryukyus), the authors wrote.
The Bohart Museum of Entomology, home of a global collection of nearly eight million insect specimens, houses 20 specimens of V. mandarinia. The largest one, a queen, measures about an inch and a half long, Kimsey said.
“Insects introduced in the United States often come in cargo boxes from Asia to U.S. ports, establish colonies, and expand their range,” she said.
The only known European hornet to colonize the United States is Vespa crabro, introduced on the East Coast in the 1800s. “It is now fully established in the southeastern U.S,” Kimsey said. “A decade or more ago, there was a colony of another species, Vespa asiatica, reported near the Port of Long Beach but nothing ever came of that.”
What's next for the research team? "We will be continuing to create online identification tools and a detailed website," Kimsey said.
"From 2010 to 2018, there have been close to 50 interceptions of Vespa (hornets) and Vespula (yellow jackets (Vespula) at U.S. ports of entry. Little less than half of those interceptions were hornets. The Vespa species intercepted include V. bellicosa, V. crabro, V. orientalis, V. mandarinia, and V. tropica. One of the interceptions of significance was an entire nest of V. mandarinia containing live brood and pupae that was sent via express courier from Asia. All species of Vespa, except V. crabro, which is already introduced into the eastern United States, are considered of quarantine importance by the USDA-APHIS."
A website, Invasive Hornets, part of a cooperation between the USDA, Animal Plant Health Inspection Service (APHIS), Plant Protection and Quarantine (PPQ) and the University of Georgia, is taking shape. According to the journal article: "This website contains more than 1,000 stacked, high-quality images of all the species and most of the races of the genus Vespa. It is important to have the resources for the identification and prevention of introduction of non-native species and to understand the potential effects of invasive hornets in our ecosystems. Hornets are dangerous for the beekeeping industry because they can alter pollination in agriculture and disrupt the beekeeping industry, as well as create public health and safety problem."
The authors credited senior museum scientists Christine Lebeau of the American Museum of Natural History and Steve Heydon of the Bohart Museum of Entomology “for helping to process the loan of Vespa material.” Mary Burns of the National Identification Services (NIS) of the USDA-APHIS- Plant Protection and Quarantine (PPQ) provided information about the number of interceptions of Vespa at U.S. ports of entry.
In an article posted in Entomology Today, science writer-educator Leslie Mertz wrote that the team is "building a publicly available, online adjunct to the newly published key that uses menus of distinguishing characteristics, as well as illustrations and photographs. They hope to have the online key up and running in 2021.”
Entomology Today publication, "Big, Beautiful, and Confusing: Deciphering the True Hornets"
“It's no more likely to sting and kill a human than a honey bee,” said Kimsey, a two-term past president of the International Society of Hymenopterists, an organization that studies bees, wasps, ants, and sawflies.
“Actually it's less likely, as honey bee venom packs quite a punch and it is exclusively designed to defend against vertebrates,” she said.
“The colony everyone is hyperventilating over was actually found on Vancouver Island, British Columbia, last September when it was destroyed and then a single, dead hornet was found in December in Blaine, Wash.,” Kimsey said. “There is no evidence that there are any more hornets in the vicinity of Vancouver or anywhere else on the West Coast.”
A colony of the Asian giant hornet (AGH), Vespa mandarinia, was found and destroyed Sept. 18, 2019 in Nanaimo, Vancouver Island, and the single dead hornet was found Dec. 8, 2019 in Blaine.
These were the first detections of this species in North America, but there may be more, according to the Washington State Department of Agriculture (WSDA). Beekeepers have reported “observations” (which may or may not be the same species) dating back to October 2019, WSDA says.
Twenty Asian giant hornet (AGH) specimens are housed in the Bohart Museum of Entomology, home of a global collection of nearly 8 million species. The largest one, a queen, measures about an inch and a half long, Kimsey said.
Meanwhile, entomologists are bemoaning the name, "murder hornet" and the sensationalism and fear-mongering ensuing.
“Some poorly-worded media reports about Asian giant hornets have triggered a veritable avalanche of nonsense online, but I can help set the record straight," wrote senior museum scientist and hymenopterist Douglas Yanega of the UC Riverside Entomology Research Museum.
“One colony was found and exterminated in Nanaimo on Vancouver Island in September of 2019, with a few sightings associated,” Yanega wrote. “One wasp believed to be from that colony was found--dead--on the U.S. side of the border near Nanaimo in December. Right now, all the authorities are doing is asking people to keep their eyes peeled JUST IN CASE there were queens that escaped the destruction of the Nanaimo nest, and established their own nests nearby. I was one of the authorities brought in to consult on this case, and to my knowledge there have not been any sightings in 2020 that would suggest the eradication attempt was unsuccessful. Put bluntly, as far as we know, there are no Asian giant hornets alive in either the U.S. or Canada as of 2020, and if there are, then they would be in the immediate vicinity of Vancouver Island (about a 50 mile radius or so).”
Said Kimsey: “A decade or more ago there was a colony of another species, Vespa asiatica, reported near the Port of Long Beach but nothing ever came of that either. A European species, Vespa crabro, was introduced into the East Coast perhaps a century ago and it is now fully established in the southeastern U.S.”
Kimsey says insects often come in cargo boxes from Asia to U.S. ports, establish colonies, and expand their range.
A soon-to-be-published article in the Entomological Society of America's journal, Insect Systematics and Diversity, promises to shed more light on the genus and the history of introductions in the United States. Kimsey and colleagues Allan Smith-Pardo of the USDA and James Carpenter of the America Museum of History, New York, co-authored the review article.
In the abstract, the authors define Vespa as social wasps that are “primarily predators of other insects, and some species are know to attack and feed on honey bees, Apis mellifera, which makes them a serious threat to apiculture.”
“Vespa nests can be physically large, with over 1,000 workers, but usually with hundreds of workers,” they wrote. “Nests can be aerial, attached to tree branches or in shrubs, in crevices, under eaves or underground depending on the species. Depending on the latitude, nests can be either annual, started by a new queen every spring, or perennial, where young queens take over from old ones. Colonies in warm tropical climates tend to be perennial.”
Washington State University Extension has published an AGH fact sheet, the work of the husband-wife team of Susan Cobey, bee breeder-geneticist and Timothy Lawrence, county director of Island County Extension (both formerly of UC Davis), and also Mike Jensen, county director of Pend Oreille. (See https://bit.ly/2SA3TxS)
The WSU scientists wrote that AGH “is the world's largest species of hornet, native to temperate and tropical Eastern Asia low mountains and forests. The hornet is well adapted to conditions in the Pacific Northwest.”
“The primary purpose of venom is defense against predators by inflicting pain and damage,” they wrote. ”Vespa mandarinia is one of the two most venomous known insects in the world.. The amount of venom each wasp delivers (4.1 μl/ wasp) has designated V. mandarinia as the most venomous insect. In comparison, the honey bee has about 0.6μl/bee. When foraging for food in spring, the AGH is not highly defensive – unless its nest is disturbed. Late summer and fall, with the high demand for protein, they become very aggressive when attacking or occupying a honey bee colony.”
“It is critical that we identify, trap, and attempt to eliminate this new pest before it becomes established and widespread,” they wrote. “Attempts to contain the spread and eradication of this invasive insect will be most effective in trapping queens during early spring before their nests become established. Finding the nests can be a bit of a challenge. Their nests are typically in the ground though they can also be found under overhangs and within wall voids. The AGH is a strong flier and often will fly up and away and have an extensive flight range. Thus tracking can be difficult.”
They advise residents to “proceed with extreme caution and contact WSDA immediately. Do not try to exterminate the nest yourself.”
Cobey, who examined specimens in Japan last December and shipped some to WSU, commented this week that “I see they have already taken on the media name, murder hornets."
The sensationalism on the media is a concern, said Lawrence, "but...we need to find out just how extensive this infestation is."
Facebook users are posting images of so-called Asian giant hornets that are actually such species as cicada killers, European hornets, southern yellow jacket queens, sawflies, hoverflies, a beetle, and a moth.
“Yes, it is possible this species could establish,” wrote parasitoid wasp specialist and educator Sloan Tomlinson. “Has it yet? No. Until concrete evidence is presented about any further establishment by this species, it's simply conjecture. Additionally, even IF this species is established, their infamy is overhyped and sensationalized. In Japan they do indeed kill around 30 people a year. Around 40 people are killed annually in the US by domestic dogs.”
Doctoral candidate and researcher Ellie Field of Iowa State University wrote on Facebook that “the murder hornet articles are making the rounds quickly and they seem to be doing more harm than good. Yes, it is awesome to track insect populations (particularly staying watchful for non-native and potentially invasive species). But no, the Asian giant hornet (Vespa mandarinia) is not going to destroy America. The one nest and individual that was found around Vancouver last year was destroyed, and this doesn't indicate any establishment. Introduction events happen all the time, all across the world! That region should continue to keep a watchful eye, but for everyone else this is not going to be relevant. There is no invasion, just a small possibility that some may have overwintered in that area.”
Those unsure about insect identification can email an image to Lynn Kimsey at email@example.com or contact the Entomological Society of America at https://www.entsoc.org/ or https://bit.ly/2W2jRmi.