BLAINE, Wash. - More than 500 "murder hornets" in various stages of development were found lurking inside the first Asian giant hornet nest ever discovered in the U.S., state agriculture officials said Tuesday.
The nest, which was found in an alder tree near the Canadian border in northwest Washington state after months of sleuthing by state entomologists, was eventually cut open after hornets were vacuumed up and the tree was removed, said Karla Salp of the state Department of Agriculture.
She said entomologists needed to inspect the nest to find out what it concealed and to collect data that will help them to eradicate the invasive insects, which attack and kill honey bees that local farmers depend on to pollinate crops.
The nest was just over eight feet high in the tree and, once opened, was found to be about 14 inches long and 8 to 9 inches wide. Here are the preliminary results of what entomologists found in the nest:
- 6 combs – There were six layers of comb in the nest. Combs are the structures that hold the hornet larvae as they develop. Part of the interior of the tree had been chewed away to accommodate the combs.
- 776 cells – The combs are made up of cells and each individual cell can hold a developing Asian giant hornet. (The number is approximate as there was some damage to the combs.)
- 6 unhatched eggs – These eggs were all located in the last and smallest of the combs.
- 190 total larvae - The larvae are whitish “grubs” in uncapped cells. Many had fallen out of the combs into the tree cavity during the nest removal.
- 108 capped cells with pupae – Pupae are the next stage after larvae. Based on the size of the cells, most of the pupae found are believed to be pupae of new virgin queens.
- 112 workers – This total includes 85 workers that were vacuumed out of the nest on Oct. 24. All of the workers survived being vacuumed out of the nest.
- 9 drones – Drones are male hornets and they generally emerge from the nest before the new queens emerge.
- 76 queens – Most likely all but one queen would be new virgin queens. New queens emerge from the nest, mate, and then leave to find a place to overwinter and start a new colony the next year.
Despite multiple applications of carbon dioxide, removal of the workers, and storage in a cold facility, most of the specimens were still alive when the nest was opened.
State agriculture agents say they will continue trapping Asian giant hornets through at least Thanksgiving and possibly beyond, but will likely only track worker hornets, since they are the most likely to lead entomologists back to a nest.
State experts previously have said they believe there are at least two other murder hornet nests in Whatcom County.
Even if no other hornets were to be found, the Department of Agriculture will continue to trap for at least three more years to demonstrate the area is free from Asian giant hornets.
State entomologists also are working with experts across the border in Canada who also are trying to eradicate the hornets there.