PEI

What actually happens when a mosquito or blackfly bites you

P.E.I. is enjoying a warm summer, but the heat comes with strings attached: mosquitoes and black flies.

Blackflies saw off your skin, says bug expert

A mosquito breaks human skin with its proboscis, says research scientist Christine Noronha. (James Gathany/Centers for Disease Control and Prevention/Associated Press)

P.E.I. is enjoying a warm summer, but the heat comes with strings attached: mosquitoes and blackflies.

Agriculture Canada research scientist Christine Noronha spoke with Island Morning's Mitch Cormier to shed light on the pests' behaviour.

Mosquitoes are attracted to the carbon dioxide exhaled by humans, Noronha says. When they get closer, they sense the odour created by a combination of sweat and bodily chemicals.

"They're attracted to that odour and that's when they home in on you," said Noronha.

'Search for a blood vessel'

When it comes time to bite, a mosquito breaks the skin with its proboscis — a straw-like mouth part, Noronha said.

'The reason why you don't feel it is because they inject an anaesthetic into that area,' Christine Noronha says of blackfly bites. (Submitted by Agriculture Canada)

"They put it into you and then they search for a blood vessel so they can start imbibing the blood. When they do that, they also inject some of their saliva into your body."

The saliva is an anticoagulant that helps the mosquito draw blood easier. It's a foreign substance that results in an allergic reaction, Noronha said.

P.E.I. is seeing a normal mosquito population this year and the hot weather is conducive to their growth, Noronha said. A female can lay up to 500 eggs. The female's lifespan varies from a month to six weeks, depending on the temperature.

A bite from a blackfly is different than that of a mosquito, Noronha said.

'It saws off your skin'

"The mouth part they use to bite you is actually like a saw, so it saws off your skin. The reason why you don't feel it is because they inject an anaesthetic into that area."

A blackfly bite usually results in seeing some blood later, she said.

Noronha suggests skipping perfume or hairspray and not wearing dark-coloured clothing, as those things attract the insects.

Mosquitoes will continue to bother people enjoying the sun until at least September, Noronha said.

More P.E.I. news

With files from Mitch Cormier

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