Officers from the National Parks and Wildlife Service (NPWS) are confident no young queens have escaped from the two Asian hornet nests discovered in Cork, so these populations will not be able to continue to breed in Ireland.
Queens are the only ones able to survive the winter as all the others die off.
Nevertheless, following the killing and removal of the second nest yesterday, this time in Cobh, NPWS will keep monitoring both that site and the one in Ballinlough, Cork City, for the next few days.
NPWS conservation ranger Sam Bayley said the Cobh nest was half the size of the one discovered in the city.
It was removed following a three-hour operation and, like the other, is being sent to the National Museum of Ireland for analysis. Mr Bayley said:
We estimate that the nest in Ballinlough could have contained up to 2,000 hornets, but the Cobh one had probably less than 1,000.
“The difference is the queen in the nest in Cobh may have started laying later, or wasn’t as good at laying as the one in Ballinlough.
The National Parks and Wildlife Service team removing the first Asian hornet nest ever found in Ireland: Claire Deasy, NPWS, Sam Bayley, NPWS, and David Law of David Law Tree Care. Picture: NPWS
“They [Cobh] may have built a first nest that failed and moved on, or there may not have been the right type of food in that area. There are many variables.”
DNA testing will now take place on the dead hornets to see if they spread from ever- growing colonies in either France or England.
Mr Bayley said in both cases, the nests were found high up in trees.
The Ballinlough nest was 19m up in a sycamore tree, while the Cobh nest was 12m up in a beech tree.
“Both were located on private properties and the landowners were amazingly helpful to us,” he said.