Originally from Asia, the greater banded hornet, Vespa tropica, is causing great concern among Guam beekeepers. First recorded on Guam by the University of Guam Entomology Lab on July 12, 2016, it is unclear how the hornet came to the island or exactly when it arrived.
UOG graduate student and president of the Guam Beekeepers Association, Chris Rosario, meets regularly with beekeepers around the island and many have reported seeing the greater banded hornet kill bees, and in several instances, wipe out entire hives. “When Master Beekeeper Paul Packbier opened a hive under attack by the hornet, he found over 30 hornets inside the hive. All the bees were dead,” said Rosario, “We have been experimenting with our own trap designs, which not only exclude the hornet but also trap them while allowing bees to enter the hive.” Rosario is currently developing a grant proposal to fund the management of Vespa tropica.
Packbier is on the warpath. He keeps a yellow fly swatter by the door of his office, where a beehive sits just outside his window. When he sees a hornet checking out the bees he grabs the swatter, runs outside and dispatches it. Although it does feel good to swat the hornet, he knows this is not very effective. He has designed and is experimenting with a prototype hornet trap. “After doing some research I found that beekeepers in Europe have issues with hornets as an invasive species and have been working on effective traps. Unfortunately, a company that has developed a promising design does not ship to Guam, so I am in the process of designing a trap for use here. The most heartbreaking evidence of the greater banded hornet’s destructive impact is seeing the mostly empty combs of feral (wild) beehives around the island. Without the relative protection of the wooden hives we beekeepers provide, the bees are defenseless and the hornets can wipe out a colony in a matter of days,” lamented Packbier.
UOG entomologists Ross Miller and Aubrey Moore, and Rosario will be attending the Entomological Society of America annual meeting in Canada next week. Rosario and Miller will be presenting a poster on greater banded hornet nests and the threat these hornets pose for bees on Guam. “This hornet poses a serious threat to beekeepers in Hawaii and the US mainland, should it arrive there. Since it is on Guam, the chances of that happening are quite high,” said Miller. Rosario is hopeful, “We want to connect with specialists at the meeting who can help us with this serious problem.”
The public is invited to contact Rosario with sightings of greater banded hornet nests at 487-1640 or via email at email@example.com.
The Guam Department of Agriculture, Biosecurity Division can also be contacted for greater banded hornet nest sightings at 475-PEST or 475-1427.