British Columbia

When wasps attack: how to dodge the summer sting

It's the perfect time of year to host a backyard barbecue — and unsuspectingly invite a horde of yellow jackets to the feast.

One sting often leads to another, according to wasp expert

A wasp with yellow and black stripes is seen in a close up as it crawls along a nest.
On average, three to four Canadians die per year from wasp stings, experts say. (John P. Ashmore/Shutterstock)

It's the perfect time of year to lounge in the backyard to the delightful tune of a searing barbecue — but once the burgers and hotdogs come off the grill, a horde of yellow jackets might show up to join the party.

When the weather warms, many wasps scavenge for protein, which is likely why you often find them hovering over your dinner plate, according to wasp expert and biologist Sean McCann.

"That's a perfect situation for these wasps to come and try to get some meat to feed the larvae back at the nests," said McCann.

Many people react in different ways. Some attempt to swat the buzzing beasts, while others involuntarily flail their arms and run for the hills. 

Wasp stings can be fatal, and according to McCann, it's important to remain calm and measured. Yellow jackets will only sting when they sense there's a threat.

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One sting leads to another

On average, wasp stings kill three to four Canadians per year. In 2014, a Quebec mayor died after she was stung 15 times.

Last summer, three people died of wasp stings in Manitoba.

According to McCann, one sting can often lead to many more.

"When the wasp stings you, a component in the fluid that the venom is contained in is actually an alarm pheromone that the other wasps can smell," he said. 

"As it stings you, some of the venom might be deposited on your skin — and other wasps can smell that and know that it's you that they need to be attacking."

Nests in areas that are regularly frequented by humans should be removed in order to avoid an attack. (CBC)

How to avoid stings

McCann says a wasp will only sting when it senses it's defending its life or defending the sanctity of its colony.

If you plan on eating outdoors during the spring or summer, setting aside an unguarded piece of meat could attract wasps away from your plate. But if you have allergies or are deeply afraid of getting stung, it might be best to eat inside or behind insect netting, he says.

And if they get close, remember to keep calm. Wasps look for motion when on the offensive.

"If you stay still and you don't get in their face, you're not likely to get stung," he said. "If you try to grab them or otherwise interfere with them, they might sting you."