Researchers Map Possible Murder Hornet Spread in the US

In December of 2019, Asian giant hornets—a.k.a. “murder hornets”—popped up in the US for the first time ever. Now, officials in Washington State say there may, in fact, be a nest of the flying insects. And one team of researchers has even taken on the task of mapping out the likely way the hornets would spread throughout the US should they gain a foothold.

A team of researchers has modeled the growth of murder hornets in the U.S. without mitigation efforts.

Gengping Zhu Et al./PNAS 2020

The map of the murder hornets’ potential spread (above) is outlined in a recent study the researchers published in the journal, Proceedings of the National Academy of SciencesIn the study, which comes via Science News, the researchers say they’ve modeled the most likely areas in which the hornets would populate as they move outward from their original location—an area near the cities of Blaine and Bellingham in Washington.

“There is a considerable amount of suitable habitat along the West Coast and our dispersal simulations of how quickly the invasion might spread were surprising to us,” David Crowder told Science News. Crowder, an entomologist at Washington State University who co-authored the study, added, fortunately, that “it is highly unlikely, if not impossible, that the hornet could traverse the continent on its own, given the lack of suitable habitat in much of the central US.”

In order to speculate on the hornets’ spread, the scientists generated a model based on two primary factors; the climate conditions in which the bugs thrive, and data regarding how the hornets’ relative, V. velutina, has invaded Europe. (V. velutina first turned up in France in 2003, and has since then been spreading throughout the continent.)

The model shows the hornets spreading as far north as Glacier Bay in Alaska and as far south as northern California. The hornets would also, according to the model, likely move inland, covering the western halves of both Washington and Oregon. But the good news is, the murder hornets only spread at an average rate of 60 miles per year. This means it would take ten years or more for the hornets to make it to these outer geographical bounds.

This model is “telling a more positive story than it’s being made out to be,” Douglas Yanega, from the University of California, Riverside, told Science News. Yanega, who was not involved with the study, added that the researchers are “talking about two decades before [the hornets] will reach the limits of its distribution. That’s a very long time.”

On top of that, this model assumes no mitigation efforts. And that’s already not the case, as Washington’s Department of Agriculture is even now trying to eliminate the hornets’ nest. (If there even is one.) This effort doesn’t mean the hornets will necessarily be eradicated, however. The first obstacle, tracking the murder hornets in order to find their nest, has already proven to be a challenge.

Feature image: Rushen