Are there more mosquitoes than usual this year? University of Manitoba entomology instructor Jordan Bannerman says when looking at mosquitoes, there are two main factors: heat and water.
He says the higher the temperature, the quicker mosquito larvae develop.
“We’re coming off several weeks of very very warm weather,” he says. “And that just speeds everything up.”
The larvae will usually develop in small sections of stagnant water.
“If those remain filled long enough for them to develop, that’s when you start to see populations build,” says Bannerman.
He says mosquitoes will lay multiple batches of eggs if possible.
“They produce as many generations as they can based on temperature and availability of water,” he says. “So, last year, since there were fairly high populations, there were a lot of eggs being laid.”
Bannerman went on to say that those offspring may not be the ones we’re seeing today.
“At this point, though, in June, we’re not really talking about those mosquitoes hatching from the eggs that overwintered, we’re kind of a generation or two beyond that,” he says. “So, the real reason why you’re seeing probably more at this time of year is because the populations have had a chance to build — they’ve had good enough conditions during this spring to get those numbers to be noticeable.”
Looking ahead to the rest of the summer, Bannerman says it’s too early to tell.
“It’s a very dynamic situation,” he says. “Mosquitoes are completely driven by the weather.”
If the next few weeks are very dry and breeding areas dry up, there could be a major drop in numbers. If there’s consistent rainfall keeping the breeding areas filled, then the population could still continue to build up.
Bannerman advises using repellant with DEET in it. He says wearing light-coloured long-sleeved clothing can also help.