“We responded quickly to this threat, but we need the public’s help to eliminate any further risk.”
Some of the characteristics of yellow-legged hornets; a queen of the species has been found in NZ for the first time. Photo / Buckeye Yard & Garden, Ohio State University
Inglis said the hornet is “a highly adaptable predator with a broad diet, primarily feeding on bees, wasps and flies, but also ripe fruit and flower nectar, posing a risk to growers”.
“It may compete with native insects and birds for food, and it has a painful sting.”
Female hornets will protect themselves by stinging and can sting repeatedly. Getting too close to a hornet nest or disturbing them in flight may result in an attack.
If you are stung and experience shortness of breath, a rash or pronounced swelling, seek medical attention immediately. If you are stung on the mouth, face or neck, or if pain and swelling persist for a few days, seek medical advice.
Two male yellow-legged hornets were spotted earlier this year in Grafton and Albany.
“New Zealand is fortunate to be free of hornet populations, and we want it to stay that way,” Inglis said.
After the discovery, Biosecurity NZ said it wants to hear from anyone who has seen the insect.
North Shore councillor Richard Hills said the discovery was significant and should be taken seriously.
“Any new species that can impact on our native biodiversity and our export industry should be treated with caution.”
Councillor Richard Hills is urging locals to follow biosecurity advice vigilantly. Photo / Alexia Russell
Hills cautioned vigilance, warning the hornets “are a significant threat to our honeybee population which in turn could threaten many of our native species and the creation and export of honey, which is important for the New Zealand economy”.
Hills urged the public to follow the advice of biosecurity officials. “Everyone should check the MPI [Ministry for Primary Industries] website for more information and report any unusual nests or insects that resemble this hornet, or anything unusual you spot when outdoors this summer. Please call MPI before you spray or remove any nests from your home or garden.”
What does a hornet look like?
The yellow-legged hornet is large (2cm to 3cm long) with a black head and a yellow face, black thorax, and legs with black femur and tibia and yellow tarsis.
Between the first and second abdominal segment is a narrow yellow band, and the fourth abdominal segment is yellow, with the remainder being black or dark brown. Unlike other common wasps the wings of a hornet are a smoky brown colour and not transparent.
A hornet is a type of wasp. There are five species of social wasps currently established in NZ. These wasps are all much smaller than the yellow-legged hornet, measuring between 11mm and 16mm.
A yellow-legged hornet (left) compared with species established in New Zealand: German wasp
(Vespula germanica, second left), Asian paper wasp (Polistes chinensis) and Australian paper wasp (Polistes humilis). Photo / Biosecurity New Zealand
What does a yellow-legged hornet nest look like?
Yellow-legged hornets construct large nests up to 60cm wide to 80cm tall, usually high up in trees or under the eaves of buildings.
It suspends many layers of cells together and “wraps them up” to form a football-sized structure.
Chinese and Australian paper wasps also like to construct aerial nests in similar locations to the hornet. However, they can be easily distinguished from hornet nests as the cells of paper wasp nests have open rather than wrapped cells.
German and common wasps (established in NZ) construct large nests that look quite similar to that of the hornet nest, but these are usually built underground. If the nest is constructed above ground, they are not usually attached to branches of trees and shrubs.
What to do if you spot a yellow-legged hornet
Members of the public are asked to report any sightings of suspected hornets or hornet nests online, or by calling Biosecurity NZ’s exotic pest and disease hotline on 0800 809 966.
Do not disturb a nest if you see one, instead photograph it and contact Biosecurity NZ.