But another nest at L’Ancresse is still eluding experts.
A couple of sightings were made of the invasive insect around Sandy Hook, leading to concerns there was a nest.
Asian Hornet Strategy project co-ordinator Francis Russell said two sightings had been made 640m apart, making it likely there was a nest in the area.
Field officer Damian Harris went to inspect the area and saw a large sweet chestnut tree. Knowing that a previous Guernsey nest had been found in the same species, he took a closer look, and spotted the nest – about 40cm across and built around a branch.
Mr Russell said people in the area were notified and the nest was removed on Monday.
It was the first secondary – or mature – nest found in Guernsey since 2019.
Mr Russell said the nest was now in the freezer.
‘We are very relieved to get one large hornet nest treated,’ he said.
‘This shows that you can have a large hornet nest up a tree and not even know about it.’
He said the property owners had dogs and were often in the garden, yet had not seen any hornets.
‘It shows the challenge we face,’ he said. ‘Even in a densely populated area, it can go undetected.’
This is the first nest that has been found in a built-up residential area. All occupants within 100m were contacted and informed of the nest removal and advised to keep windows and doors closed during the morning.
Volunteers from Guernsey Civil Protection ensured no members of the public were in the immediate area while the nest was being treated.
All hornet activity around the nest ceased within an hour after treatment.
The nest will be dissected to see if queens had started to mature. They could have gone on to make new nests.
‘We hope it will all be worker hornets inside.’
The nest was too far from L’Ancresse to account for a separate sighting of an Asian hornet there, meaning there is likely another nest.
‘It’s a bit mystifying,’ he said. ‘If it was a big nest we would expect to see more flying.’
There have been two secondary nests in Alderney this year, one of which has been found and is being removed. So far there have been no nests found in Herm or Sark this year.
n Any suspected sightings should be reported by email to email@example.com or 07839 197082.