Heavy rains produce a second type of perfect storm: mosquito breeding

Insect experts say this week’s rain has created a perfect storm of another kind, for mosquito breeding, waking up what has so far been a relatively benign skittering season.

However, it may be too early to tell whether the city’s mosquito population will be larger than normal, as weather conditions play a large role in their life cycle.

The City of Calgary actively monitors mosquitoes as part of its Integrated Pest Management (IPM) plan, with technicians checking water samples for larvae, an early stage in the mosquito life cycle.

Officials said heavy rains mean mosquitoes have more habitat to lay eggs in pools of still water, which then grow into larvae and five to 10 days later turn into adult-sized mosquitoes.

“We’re going to see more mosquito habitat there, which means in the coming week we’re definitely going to start seeing more adult mosquitoes,” said IPM technician Alex Pepperdine.

However, she said the resulting population will seem outsized compared to early spring simply because the city experienced dry conditions before the wet weather event.

“It’s been pretty quiet so far, so people might start noticing it more just because there really hasn’t been a lot of activity,” she said.

With more eggs in the water, more mosquitoes will grow. However, Pepperdine said warm weather after heavy rains will speed up the life cycle of mosquitoes, which helps determine whether the population will be larger or smaller.

Pepperdine said officials will know more once adult mosquitoes fly.

HOW TO MANAGE MOSQUITOES

She also has some recommendations for dealing with mosquitoes.

The first step is prevention.

Pepperdine said Calgarians can throw away any empty flowerpots, buckets or toys that may have collected water, to prevent mosquitoes from laying eggs or allowing larvae to swim and mature.

With more eggs in the water, more mosquitoes will grow. However, Alex Pepperdine said hot weather after heavy rains will speed up the life cycle of mosquitoes, which helps determine whether the population will be larger or smaller.

She also recommends insect repellent with enough deet.

Mosquito repellents can be harsh on human skin. So she also recommends wearing long-sleeved clothes outdoors and limiting activities at dawn and dusk when mosquitoes are buzzing.

She adds that mosquitoes are attracted to the carbon dioxide that humans exhale, and limiting activists who need heavy breathing will also help reduce mosquito bites.