Warm damp conditions are right to fuel a potential boom in insect numbers this summer. Photo: 123RF
The fly population is likely to boom in the next month because of warm, damp weather in many parts of the country, pest experts warn.
The conditions created ideal breeding conditions for flies, mosquitoes and other bugs like ants.
Debug Nelson owner Shane Warland said he was expecting flies to boom this summer in particular.
"I think we're going to have a major influx of flies ... the last couple of years hasn't been too bad, but I really thing this season they're really going to bounce - they're going to take off."
Pest Management Association vice president Dr Paul Craddock told RNZ that flies were climate-driven creatures with a life cycle of about a week, so with ideal fly breeding conditions now, people should expect a lot of them to be about later this month.
However there were some simple steps people could take to keep them away from houses.
Listen to the full interview here
"It's been a very warm summer, we had a fairly warm winter and pretty wet spring and it's been raining a lot over the week or so, so that creates perfect conditions for insects - they like it when it's warm and they like it when it's damp - so their populations we're predicting within the next few weeks will start to boom," Craddock said.
It was likely all insect populations would peak during this warm season, but house flies, blow flies, "those pests that come inside, and hang around the barbecue," and mosquitos would be worse, he said.
Ants and wasps would also become a nuisance.
"For flies the key thing is to try and keep them out in the first place," Craddock said.
He recommended fly screens and said flies did not like moving air, so running a fan helped drive them back outside.
"But generally it's just good hygiene - keeping your kitchen clean, making sure you've got no smelly rubbish or smelly cooking smells and things like that, put your rubbish outside in a sealed lid as far away from the house as possible and have a bit of a look around the garden, make sure your compost bin is in good condition and as far away from the house as possible, you've cleaned up any dog faeces or any thing like that," and remove any piles of grass clippings, as they created a perfect place for flies to lay eggs.
"That reduces the attractiveness. Flies are just going to come inside because of the smells, and they like being inside because it's nice and still, so if you change those conditions they'll move away."
Craddock said as weather patterns shift due to climate change we would see different patterns from bugs.
Insects could adapt rapidly to changing conditions, and would likely increase in numbers with a warmer climate, but in areas where there were extended droughts their numbers could actually drop.
"But overall they'll adapt to change, and they'll do it rapidly," he said.
"They're fast breeders, so when conditions are right they start breeding and all these babies survive and so all of a sudden you get exponential growth."
Flies could spread food-bourne illnesses, but the problem was greatly reduced if houses were kept clean, he said.
"They're out there swarming around the dog faeces, and then all of a sudden they're swarming around your barbecue lunch, so you can see there's a transference of potentially bacteria and those kinds of food-bourne illnesses.
"So that's why we want to keep those numbers low and keep things clean and tidy just to stop that from happening."