They’re a buzzing annoyance, a painful pest, and a backyard barbecuer’s worst nightmare.
And even more than that, wasps are a threat to our environment and the economy, costing the country more than $130 million each year.
Martin De Ruyter/Stuff
Now it’s time to wipe them out.
Stuff, the Department of Conservation (DOC), the Tasman Environmental Trust, and Conservation Volunteers New Zealand have combined forces to track wasps and at just the right time – usually mid-to-late summer – hit the great outdoors with wasp bait.
The Wasp Wipeout started in 2016 as a local effort in the Nelson Tasman region targeting common and German wasps in the top half of the South Island.
This year it is expanding into Wellington, the West Coast, Canterbury, Central Otago and Auckland, and will go after the harder-to-target paper wasps as well.
New Zealand has some of the highest wasp densities in the world, with up to 40 nests per hectare of forest – a biomass that dwarfs rodents, birds and stoats.
A DOC report, released in 2015, estimated that introduced wasps cost New Zealand’s economy more than $130 million a year, with the biggest economic impacts on farming, beekeeping, horticulture and forestry workers.
Last year, the Wasp Wipeout raised more than $80,000 towards clearing South Island forests of their most effective predator, covering more than 30,000 hectares of bush.
Wellington Pest Control managing director Darren Labrum said the number of wasp nests the company exterminated in Wellington was increasing every year.
Last year, they completed 102 nest jobs, 87 in 2017, 79 in 2016, 82 in 2015, and just 60 in 2014.
“Since we’ve been in the business, for about 20 years, it’s definitely becoming more of an issue.”
Warmer temperatures brought on by climate change were to blame for wasps becoming frequent in Wellington, whereas they’d traditionally been more of an issue in Auckland, Nelson and Hawke’s Bay, Labrum said.
“Now with climate change, temperatures are warming and more and more places in New Zealand are becoming favourable … we’re seeing them in areas you wouldn’t have used to.”
Pestproof director Paul Chapman said in peak times his company in Wellington exterminated about nine wasp nests every day.
“My advice to people is if they see a solitary wasp at this time of the year, if they kill it, then it could prevent a nest from starting.”
The wipeout’s bait of choice Vespex was efficient if it was used on a large scale, he said.
Vespex is a protein-based bait designed and administered to target wasps with as little risk to other animals or insects as possible.
The active ingredient, fipronil, is at a concentration of 0.1 per cent, a lower concentration than the same active ingredient found in common flea-treatments for cats and dogs.
A 2017 study found that in just four days Vespex reduced wasp numbers by 94 per cent, and longer exposure had an up-to 98 per cent reduction in the wasp population.
The poison needs to be re-administered every year as a queen wasp can fly vast distances – up to 70 kilometres – to find the perfect spot to build her nest.
Just one queen can re-infect an area to the tune of thousands of individual wasps stripping the forest of honeydew, nectar, and insects.
The costs to the environment is high, with multiple studies showing that the overwhelming presence of wasps can put native insect populations in a tailspin, and effectively take out the food sources that native animals rely on.
Vespex wipes out entire nests in one hit, thanks to the way wasps eat. Though the adult drones are the ones gathering all the honeydew and insects from the bush, they actually have very poor digestive systems and can’t digest any of it themselves.
Instead, the wasps bring everything back to the nest and feed it to the larvae, which then feed the adults with a pre-digested meal.
Paper wasps are trickier to target, because unlike the more opportunistic vespula (common and German wasp) species, paper wasps only eat live insects.
This, as well as paper wasps’ preference for more urban areas, means tackling paper wasps has to be a communal effort, usually involving a can of spray.
WASP OR BEE?
Honey bees are a valuable part of our ecosystem and shouldn’t be harmed, but wasps feed on beehives and have been known to dive from the sky to attack beehives.
It may be hard to tell the difference – wasps tend to fly faster and more erratically than bees, making them tough to identify.
They have very different natures – a bee will be gentle in nature, while wasps can act aggressively and are often ready to sting.
Honey bees are a warm yellow or orange, with a shorter body, and a wasp’s longer body will be a brighter yellow with more defined markings.
Honey bees are fuzzy, while a wasp will have little to no hair on its body.