Parasitic wasps will be imported from the UK to be tested as a weapon against common wasps.
Landcare Research is assessing possible biocontrol agents to help control German and common wasps, which cost the primary sector about $130m each year.
Landcare Research is testing whether the common wasp can be controlled by introducing a parasitic wasp. Photo: 123RF / Landcare Research
Landcare scientist Bob Brown will travel to the UK next month to collect the parasitic wasps, and hoped they would be able to help control the common varieties.
"What they do is the adult parasitic wasp is in the nest and she goes around and she lays eggs on the larvae of the German [and] common wasp, and those develop into tiny little larvae as well, but they eat the larvae of the other wasp."
The parasitic larvae went on to pupate into wasps, but did not prey on other species, Dr Brown said.
They were also much smaller than the common wasp and did not have stings, so would not present an annoyance to humans.
The parasitic wasps had to come from the UK because they spoke the same chemical language as New Zealand's dominant wasps species, Dr Brown said.
Earlier attempts failed because the imported wasps were from a different region.
"The idea is to go back to their home range and look for the parasitoid wasp there to hopefully match the common wasp's chemistry," he said.
"The chemistry is how they communicate - they're really good at smelling very small quantities of these compounds, they're also really good at detecting intruders in the nest so putting a natural enemy in from the wrong region, even if it's the same species, the likelihood of them to go undetected in the nest is pretty small."
Dr Brown said he might have to dig into 30 or 40 nests in the UK to find the parasitic wasps he needed.
Other potential wasp control agents included a parasitic hoverfly and a parasitic fly, while mites have had limited success as a control agent.