More than 500 Asian giant hornets were collected at various stages of development when entomologists found the first Asian giant hornet nest in the United States.
However, finding the nest was only the first step in the extermination process. After discovering the nesting site, WSDA entomologists had to safely remove the hornets that lived in the nest, remove the tree, and finally split the tree to reveal the nest inside.
After the WSDA entomologists opened the tree containing the Asian hornet’s nest on October 29, they still had a lot to do to collect data on the nest. Similar to the elections, the count has taken some time and continues to some extent.
- The nest was a little over 8 feet tall in the tree and when opened was found to be about 14 inches long and 8 to 9 inches wide. Here are the preliminary results of what our entomologists found in the nest.
- 6 Combs – There were six layers of combs in the nest. Combs are the structures that the hornet larvae hold during their development. Part of the inside of the tree had been chewed away to pick up the combs.
- 776 * cells – The combs are made up of cells and each individual cell can hold a developing Asian giant hornet. * This figure is approximate because the combs have been damaged.
- 6 Unhatched Eggs – These eggs were all in the last and smallest comb.
- 190 total larvae – The larvae are whitish “maggots” in uncovered cells. Many had fallen from the combs into the tree hole while the nests were being removed.
- 108 closed cells with pupae – pupae are the next stage after larvae. Due to the size of the cells, it is believed that most of the pupae found are pupae of new virgin queens.
- 112 workers – This total includes 85 workers who were sucked from the nest on October 24th. All workers survived to be sucked out of the nest.
- 9 Drones – Drones are male hornets and generally emerge from the nest before the new queens emerge.
- 76 Queens – Most likely all but one would be new virgin queens. New queens emerge from the nest, mate and leave to find a place to hibernate and start a new colony next year.
Despite multiple uses of carbon dioxide, removal of workers and storage in a refrigeration facility, most of the specimens were still alive when the nest was opened.
WHAT’S NEXT? The WSDA will continue to catch at least Thanksgiving and possibly beyond, but will likely only track worker hornets. For example, our entomologists will not track down new queens if they are captured as they are unlikely to return to a nest and will instead try to find a mate. Even if no other hornets are found, the WSDA will remain trapped for at least three years to demonstrate that the area is free of Asian giant hornets.
The WSDA’s plague program continues to hope to work with our neighbors in northern Canada to eradicate giant Asian hornets from the Pacific Northwest. Efforts require international collaboration, research into better detection tools, and the continued work of vigilant public observers to prevent Asian giant hornets from gaining permanent foothold here.