Warm and humid La Niña weather is prompting a warning to “prepare now” for pest-management ahead of peak insect-breeding season.
A La Niña weather pattern meant warm and damp conditions in the North Island and warm but dry conditions in the South island, with a longer summer expected across the country.
The lack of rain expected for the South Island meant flies and mosquitoes were arriving sooner than expected and remaining for a longer time.
“What that means is it’s perfect breeding conditions, not only for regular crawling insects, but flying insects,” said New Zealand pest and garden expert Jane McCarrison from Kiwicare.
She told Breakfast that both Mitre 10 and Bunnings had reported a spike in the number of pest products being sold – with numbers not usually seen until December.
“So we’re seeing hot off the press from our retailers, a spike of 50% above last year on flying pest sales. So you’re not alone if you think your house is full of flies, it’s not just you.”
McCarrison said it would be those in the North Island who were in for the worst of it.
“We’re seeing with La Niña warmer sea temperatures so it’s creating that humid decaying matter around.
“With mosquitoes, they like to pool around things like stagnant water. So we’ve had more rainfall, and then where it pools on your décor and pot plants or things like that, that does create environments throughout New Zealand, but specifically in the North Island where at the moment, we’re seeing more of that humidity,” she said.
Which regions could be in for a particularly nasty summer of mosquitoes – Watch on TVNZ+
How can you prepare?
McCarrison said now was the perfect time for people to start preparing their homes and backyards, and broke it down into three simple steps.
Step one: Clean up around the home
“It sounds pretty simple, but with your rubbish bins, make sure you’ve got lids on them.
She said a couple of times a week she would wipe around the bench tops, and clean the areas where the bins were stored.
“When you’re replacing your rubbish, and the bin juice that comes in the bottom of the bins, you’ve got to get rid of that,” she said.
Step two: Kill
McCarrison said the second step was to “kill anything in the house”.
“You can use your regular point-and-shoot fly sprays to get rid of the bugs, or an automatic system,” she said.
Bug bombs were also an option.
She said for those who may worry about the chemicals in a spray around their pets, kids or themselves, it was best to set them off at a time when nobody else was home.
“Get them out of the house, set off the bug bombs during the day, and then go back in to let it air out for a couple of hours, and then it’s good to go.
Step three: Protect
McCarrison encouraged people to check commonly-forgotten areas where bugs can accumulate including doorways, eaves and car wing-mirrors before they go on holiday.
“It’s an awesome thing to do before you go away on summer holidays. So one year we came home and had fleas in the house – because we’ve got cats – but it’s because they’re sitting in those warm, humid conditions.
“So set the [bug bombs] off before you go away, and it’s a great way to protect your home and clear for pests.”
She also advised to move bins away from the entryway to the house, if possible and keep backyards free of pet waste to avoid attracting insects.
“So you’ve cleaned up, you’ve killed them inside, and then you’ve protected outside.”

