Wasp colonies in the Sea to Sky have surged in population this summer, causing a nuisance and more than a few stings for residents and visitors.
Although Vancouver Coastal Health (VCH) does not officially track patients coming in with wasp-related ailments at its health care centres in Whistler and Pemberton, VCH’s Squamish medical director Dr. Richard Cudmore told the Squamish Chief last week that it’s been the “worst summer I’ve seen in 30 years,” with Squamish General Hospital seeing four to eight people with stings per day.
It’s a trend that local exterminators have noticed as well.
“We’ve been operating in the Sea to Sky for about seven years now and it was definitely the busiest wasp season we’ve had,” said Jason Page, owner of Solutions Pest Control. “On June 10 of this year, we had exceeded our 2012 numbers completely as far as the number of nests we’ve treated.
“It’s kind of coming to an end as we speak with the cooler evenings, but we’re still getting about two or three calls a day right now, and that’s down from 20-ish nests per day we were doing through the summer.”
Dr. Ken Naumann, a Langara College instructor specializing in social insects, said weather over the past year is likely a contributing factor to the population boom.
“It might have a little to do with the relatively mild winter and the unusually nice summer that we have had,” said Naumann.
“If it’s a mild winter, you’ll have more queens successfully overwintering. If it’s a nice spring and a nice summer, you’ll have more of the young colonies surviving.”
Naumann said the late summer period is when wasps begin exhibiting more aggressive behaviour, making them more noticeable.
“Because the colonies are effectively winding out in August, what you have is a lot of relatively old foragers, and they have probably a little more venom stored away in their bodies,” he said. “To put it in human terms, they don’t have much to live for anymore. It’s the colony’s last little surge — ‘Let’s produce a few more queens, but then we’re going to die in a few weeks, anyways.’ So what do they have to lose from being really aggressive?
“Instead of coming in and sampling a little bit of fish on your plate, they’re just going, ‘Mine,’ and keep coming back.”
Naumann said wasps establish annual colonies in the Sea to Sky area, so anyone dealing with a problem nest this summer doesn’t have to worry about one returning in the same place next year.
Page said high-quality wasp traps that are effective at keeping outdoor spaces clear of the bugs can be purchased through his and other companies. However, he noted that anyone is looking to remove a nest before the end of the season should exercise caution.
“As temperatures fall, they become a lot more defensive when they’re operating during the day, so what may have been a more plausible or safe treatment for someone to do themselves even three or four weeks ago becomes more of a high-risk operation today,” said Page, who expects his company will continue dealing with wasp calls until the end of October.
Page also suggested calling in experts to deal with nests in hard-to-reach areas or ones that aren’t completely visible — just spotting an entry point to a nest isn’t enough to determine the extent of the problem.
“It could be 15 or 20 feet into an attic or wall void and there are very few products, unfortunately, on the market that are capable of treating a hidden nest like that,” said Page. “You’re much better off, from a safety … and permanent eradication standpoint, to contact a pest professional.”
Colonies typically begin dying out with the arrival of cooler weather.