Just when you thought it was moderately safe to leave your homes here come the warnings of the poorly named Murder Hornets. The images this moniker creates are like scenes from Jumanji or The Hunger Games. While the creature with which we could be dealing stand to wreak havoc on the already struggling bee population, they are not the homicidal beasts its new nickname portrays.
This newly introduced Asian giant hornet, or Vespa mandarinia, is native to Eastern, Southern, and Mainland Southeast Asia. The hornet can also be found in parts of Russia, Korea, China, and Taiwan. Its preference is rural wooded areas. While there are large wasps in our area already, called “cicada killers,” they are not to be confused with the much larger Asian giant hornet.
These larger than life invaders create their subterranean nests by usurping tunnels created by rodents, snakes, or other burrowing animals or digging spaces of their own, typically near rotten pine roots. These underground fortresses will usually consist of four to seven combs.
Unlike bees, a nest of these hornets can have multiple queens that function in a dominance hierarchy. The most dominant queen feeds while the others stand guard around her. When she is done the next ranking queen feeds in the guarded circle and so the process repeats until the final queen has fed.
When queens are inseminated in a sneak attack that often leaves males of the species dead, they will search for nesting sites. She will spend months raising a small nest of workers who will eventually become caretakers for her larvae. Late in the year, these queens will die.
While their sting is vicious it is not immediately deadly to humans. The painful sting has been compared to the feeling of “a hot nail being driven into my leg” by Masato Ono, an entomologist from Tamagawa University, near Tokyo.
The sting of an Asian giant hornet can be lethal to humans but those will typically be people who have a sensitivity or are severely allergic to bee or wasp stings as the venom is similar or people who have been stung multiple times. Chinese officials recommend that people stung more than ten times should seek medical assistance and those stung more than 30 times will need emergency treatment.
The Asian giant hornet is intensely predatory. Bees, mantises, and other species of hornet are the primary prey of this invasive species but they have been known to cannibalize each other’s colonies.
If introduced to our struggling honey bee population the results could be devastating. A single hornet is capable of killing as many as 40 bees per minute. A slightly larger group of hornets can decimate a colony of thousands of bees within a few hours.
Local beekeepers have no ideas, as of yet, on how to protect the local honey bee population. Controlling the population of these hornets once they’ve been introduced is difficult. Asian countries have developed various methods of extermination for these hornets and while they are effective they cannot eradicate the species.
In Japan, hornets are crushed with wooden sticks. This process is cost-effective but inefficient. Nest removal is another option. Poisons and fires deployed at night when the nest is inactive is an effective way of exterminating a colony. The difficulty in this lies in finding the subterranean nests. Bait traps can be placed in apiaries which will direct the hornets into a compartment from which it is difficult for them to escape. Small mesh screens are utilized so that bees can escape while the hornet remains trapped inside the snare.
When met with resistance hornets tend to lose the urge to attack so another method to deter them is to place protective screens around hives allowing bees to pass through safely. This method combined with traps is effective to a point.
All methods have some potential to deter the hornets but none to eradicate the species before it takes hold of the area. If you think you have seen an Asian giant hornet take a photo and send it to the Department of Entomology through the Texas A&M Agrilife Extension services website at https://askanentomologist.tamu.edu/insect-id-form/. If you located a dead specimen you can collect and ship them through a form found on the same site.