The giant Asian hornet scare

PHOTO COURTESY OF JIM BAKER, NORTH CAROLINA STATE UNIVERSITY, BUGWOOD.ORG Notice the size difference between a yellowjacket (bottom) and a European hornet (top).

There was a flurry of calls into the Penn State Extension office a few weeks ago about the appearance of the giant Asian hornet. I am assuming that postings on Facebook probably played a role in this excitement. And no wonder folks were worried; everything about this insect is scary!

For starters, these things are big. They are the biggest hornet in the world, measuring around 1.5 inches. Just for comparisons, a honeybee will measure around .5 inches long. With an insect as large as this hornet, one could only imagine the sting and issues with the venom.

A 2013 CNN article details the death toll of 42 people from giant Asian hornet stings in China. Not only is there the concern of anaphylactic reaction (can lead to airway closure or cardiac arrest) but the venom destroys red blood cells, which can result in kidney failure and death.

As a beekeeper, I am equally concerned. Once the hornet scout identifies a honeybee hive, it will return with nest mates, and they can wipe out the bees within a day. And it is a massacre as decapitated honeybees litter the ground from the hornet assault.

But rest assured, the giant Asian hornet has not made it too our shores yet. Its native homeland is Asia (hence the name), yet we should not rest easy. Our recent history is replete with Asian organisms that first showed up in Pennsylvania before any of the other 49 states. The most recent example is the spotted lanternfly. Go back a bit further, to 1998, and we got to experience the brown marmorated stink bug before anyone else. The stink bug is now all over the U.S.

So what are people seeing around their properties? I can’t speak for all the postings and phone calls, but based on the one sample that was brought into the office, I think most people are seeing the European hornet.

These hornets are also large, about 1 inch in length. They have been around since 1840 and their range is up and down the East Coast out to the Midwest. European hornets are not aggressive, unless they feel their nest is under attack (so respect their space and they will respect yours).

They are unique to other hornets in that they do the majority of their flying at night and can often be seen when bumping into lights and windowpanes.

The only other item of note is that the European hornet can cause damage to trees and shrubs as they remove bark for their nest.


Tom Butzler is a horticulture educator with the Pennsylvania State University Cooperative Extension Service and may be reached at 570-726-0022.