Extermination under our noses
There’s a massacre of New Zealand’s native bug life going on and community help is needed to stop it, writes Skara Bohny.
Voracious killer wasps are causing some of New Zealand’s native bugs to go extinct, insect experts believe. Last year, The Nelson Mail and Stuff launched a community campaign to wipe out wasps once and for all.
With help from the Department of Conservation (DOC), the community, and other conservation groups, the Wasp Wipeout campaign raised over $50,000 and saw a 98 per cent reduction in wasp populations.
Hundreds of volunteers set Vespex bait traps along hundreds of kilometres of DOC walking tracks and public areas, and this year the programme is expanding into a nationwide effort.
Wasps have devastating effects on native insect populations.
The lifespan of native insects in wasp-dense areas can be a matter of hours, and native species may even have been driven extinct.
Victoria University insect ecologist Professor Phil Lester says he was ‘‘sure’’ there have been local extinctions.
‘‘There must have been at least local extinctions of species, things like the forest ringlet butterfly that we just don’t see many of anymore,’’ he says.
And thanks to the hot, dry spring, it looks like it’s going to be a ‘‘bumper year for wasps’’.
University of Auckland Associate Professor Jacqueline Beggs says an imbalance in the invertebrate world can have unknown consequences.
‘‘Insects drive the food-chain, birds and other insects and lizards will feed on them. They’re doing the creation of soil, they’re often driving pollination, and nutrient turnover, just so many things. Insects are the real drivers of ecosystem functioning, so the fact that that is being impacted, as an ecologist, leaves me really worried.’’
Those ecological effects have already been playing out for decades, as common wasps have been a major problem since the 70s, and German wasps since the 1940s. But so little is known about the insect world, it is unclear what those effects are.
Bugman Ruud Kleinpaste, who has dedicated much of his life to insects, says bugs ‘‘fly under the radar’’.
‘‘We actually know very little about insects full stop. We don’t even know how many species there are, we know of about a million, there might be 12 million, 15 million, we don’t know. But even more than that we don’t know what their ecological niches are.’’
But enough research has been done to show ‘‘the overall effects wasps have on the invertebrate world is just devastating’’.
Those effects aren’t limited to native insects, either. Honey-bees are also a target, and this along with their other effects, led to wasps being calculated as a $133 million drain on the economy each year.
So wasps are costing us a healthy ecosystem, our unique biodiversity, and hundreds of millions of dollars. But we can fight back.
‘‘Vespex is a revolutionary tool,’’ Lester says.
‘‘The formulation that’s been developed is one that’s very attractive to wasps, it’s a protein matrix that’s really appealing to wasps and not other insects like bees. And when it’s nailed to a tree and only left out for a few days, that limits its non-target effects.’’
However, Beggs estimated even after a total eradication of wasps, it could still take years for insects with low reproductive rates to recover.
Kleinpaste says that since we don’t know the full effects that the wasps are having, ‘‘it will pay for us, all New Zealanders, to look after biosecurity and become natureliterate, and look after the environment’’.