Stopping Asian Giant Murder Hornets, Scientists Race Against Time in Washington and British Columbia

Asian giant hornets (Vespa mandarinia), also known as "murder hornets," pose little threat to humans but are considered a menace to beekeepers' livelihoods in East Asia. Officials are concerned that they could also cause the same problems in North America.

The three hornets spotted this spring have all been mated queens, which could mean that at least one colony had successfully reproduced in 2019. However, this does not mean that they have successfully established in North America, it would require successful reproduction over multiple generations before that happens.

An uncommon advantage might make all the difference

Entomologists from the Washington State Department of Agriculture (WSDA), the U.S. Department of Agriculture, and the B.C. government are all working together to prevent the species from completing its life cycle in the country.

They are planning to employ their program of trapping, tracking, and removal of the giant hornets to reverse the species' introduction to the country. They will use the extensive literature available about this species in Japan, where its biology has been extensively studied.

These scientists are racing against the clock. Luckily, the giant hornet's life cycle can be plotted on a calendar, giving them an advantage when to act and just how fast to move.

For instance, giant hornet queens in Japan emerge from hibernation in the spring and spend May and June establishing their nests. They would first lay eggs, which will become the non-reproductive workers that will appear by July to take over the jobs of building and provisioning the nest.

After a couple of weeks, the queen lays eggs fulltime, and the colony starts to grow, and workers become more and more common.

The strategies for detection will focus more on trapping the workers starting in July. By doing so, entomologists hope to find the nest and destroy before the end of summer because by late August to early September, they change behavior and begin attacking honeybee colonies.

Tracking giant hornets while they attack honeybee hives

A handful of attacking hornets can destroy an entire honey bee colony within a few hours. The only positive thing about this is that their attacks are easily seen, so they are also easily tracked. Once they begin attacking, authorities will now focus their efforts on investigating reported attacks.

These insects occupy the hives of the defeated bees for a few days, giving the entomologists an advantage to track the nests of the giant hornets. They will be using miniature tracking tags and heat vision cameras, which could locate underground hornet nests to help them.

By the time that attacks of honey bee hives by the giant hornets are confirmed, entomologists may only have a few weeks left to stop another generation of potential queens from reproducing. Due to that, experts will be working hard to ensure that as many nests can be located and destroyed as soon as possible.

They are also enlisting help from people to set out homemade hornet traps and report the insect's sightings using an online forum.