A hornet trap. Photo: Brad Windust / supplied
A conservationist is urging for a united Auckland front to eliminate the threat of yellow-legged hornets, calling for residents to set up home-made traps.
Biosecurity New Zealand has so far found six yellow-legged hornets, including four queens, in and around Glenfield on Auckland's North Shore.
Two of the queens were discovered in the early stages of building a nest, while the other was flying in the area.
Brad Windust estimated the hornet species has likely been on our shores for many months, and its population could now be in the hundreds, putting New Zealand's honeybees at risk - including our 27 native bees and other native insects.
"Can't muck around and wait for MPI (Ministry for Primary Industries). Everyone in that Auckland region needs to set a trap," he told RNZ.
Yellow-legged hornets (Vespa velutina) have recently been sighted in the Auckland region. Photo: Biosecurity NZ
The former Far North beekeeper and pest trapper has been outspoken in his criticism of Biosecurity New Zealand's response to the invasive insect, calling it inadequate - demanding hundreds of feet on the ground to combat the threat.
There are fears the hornet could impact our agriculture sector, including the honey industry as it hunts honeybees.
Windust said hornet traps can be made with simple household items like fizzy drink bottles.
"A good one is a dark L&P two-litre bottle and then a clear Coke bottle, and you cut them in half and you turn the top half of the clear bottle inside the bottom half of the L&P bottle."
"In the bottom you just put a bit of beer and a little bit of vinegar and that should attract the hornets."
Windust said there were different recipes which could be used for the lures, and they changed depending on the season.
"In the springtime, when the queen is emerging from hibernation, it's a sweet, sugary beer bait, and once the queen stops working and her worker hornets are going out, then the bait needs to change to a protein bait."
"From summer the mixture must be a little bit different, as the hornets look for protein during this time of the year."
"To properly trap the hornets during those months, people may mix in three litres of water, 1.5kg of sugar and 60g of baker's yeast."
"They fly into the trap and then they can't get out through the little hole in the middle, they keep flying up the sides and then they fall into the liquid and drown.
"You can also add a couple of drips of dishwashing liquid which breaks the surface of the water and makes them drown quicker."
A hornet trap. Photo: Brad Windust / supplied
Windust said there were also ways to prevent honeybees from being attracted to the traps.
"In some recipes there's a little bit of vinegar added to not attract honey bees, but in the Auckland area where the hornet has been found, that's the least of your worries.
"The most important thing is to catch the hornets, because the spread of the hornets is going to do a lot more damage to bees than traps."
He said if you did find a hornet, it was important to take a picture and report it to MPI.
Windust also said Aotearoa species identifier apps were helpful in differentiating species.
MPI put out advisories after the first queen was found on 17 October. Photo: Biosecurity NZ
Biosecurity New Zealand commissioner north, Mike Inglis, said there was no specific trap for this hornet currently in New Zealand. But he said they were aware of hornet trap designs that could be made at home which may be effective in attracting hornets and other flying insects.
Inglis warned though that significant by-catch should be expected.
"Our scientists have been evaluating potential trapping and baiting options. We are now working through a deployment plan, which is expected to begin on Monday."
"The placement of traps will be based around public notifications, which have given us a good indication of where the hornets may be."
Inglis said the yellow-legged hornet behaves similarly to other social wasps, such as the common German wasp, and there were wasp traps available in New Zealand that may attract them.
"These traps are likely to result in significant by-catch, including bees, flies and other insects," said Inglis.
"The attractants used will be either sugar or protein-based, targeting foraging queens and workers. We believe sugar-based traps will be most effective at this stage. However, as nests begin to develop, the hornets' preference is expected to shift toward protein-based baits."
Biosecurity New Zealand said to report a specimen or clear photo of a suspect hornet and a possible hornet nest to their website or pest and disease line 0800 80 99 66.
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