What’s red, black, and creepy-crawly? Admittedly a lot of insects, but lately in Ottawa, it’s the boxelder bug.
They were reported earlier this fall to be swarming Toronto homes, coating siding like horror-movie-locusts and flying into the midst of Thanksgiving gatherings. Ottawa residents have also been reporting greater-than-normal hordes during the autumn months.
However, the beetles are almost totally harmless — unlike their lookalike, the Assassin bug, the “nuisance pest” boxelder beetle does not bite or carry pathogens.
This year has seen a bumper crop of boxelders, though, with almost double the amount of bugs born according to Orkin pest control. And unfortunately, late fall is when boxelder beetles move indoors.
“They’ve been bad at my house,” said Anita Murray, a former Ottawa Citizen reporter who lives in Carp, west of urban Ottawa. However, she said, the worst instance she’s seen was at an auto shop a few miles away.
“There were literally thousands of them, swarming around the garage door and the air compressor. It was like walking through a cloud of bugs.” According to Murray, the insects have been an annoyance for many of her neighbours, too: “They really get in your face!”
Rob Caron, Ottawa district manager for Orkin Canada, said the insects are gradually growing in number. “I’ve been in the business for 24 years, and every year there seems to be a large increase in boxelder beetles.”
The reason why? “A hot, dry summer offers perfect breeding conditions,” said Canadian Museum of Nature entomologist Robert Anderson. “I think larger than usual populations are due largely to that.”
According to Caron, the bugs are harmless to humans, but can be a real nuisance to homeowners in the vast quantities seen this year. And apparently, they don’t discriminate between rural and urban neighbourhoods: “If you have boxelder trees, you’ll have boxelder beetles. They’re all over.” The bugs are also attracted to maple and ash trees.
“If you squish them they leave a big stain,” said Caron. “And in large numbers, if there’s a (boxelder) tree on your property that’s unhealthy, they’ll quickly kill it completely.”
Homeowners should keep an eye on their boxelder trees: during winter storms, dead, bug-eaten trees can pose a threat to power lines, homes, and vehicles.
Boxelder bugs are attracted to warmth, and frequently overwinter under the siding of houses, said Caron, shielded from winter winds and snowfall, but still warmed by the sunlight.
Unfortunately, said Anderson, some of the bugs can get a little ambitious: looking for warmth and security, some boxelder beetles attempt to hibernate indoors. During years with higher bug populations, instances of invaders may be higher.
Caron said that boxelder bugs typically enter the home through cracks in a house’s foundation or walls, much the same way that mice do, or fly in as hitchhikers when people are entering the home. Caron was, however, quick to emphasize: boxelder beetles will not infest the interior of a house, as their preferred diet is trees. If a house has a few adventurous invaders this fall, homeowners are advised to give carpets a quick vacuum to avoid stains from squashed beetles.
Both Caron and Anderson recommended spraying the beetles with cold water if siding or trees are being swarmed. Neither Caron nor Anderson suggested spraying the bugs with insecticides, as it may kill beneficial species in the process.
“I guess it’s an issue of appearance and how freaked out you are by having all these bugs crawling over your house,” said Anderson. “They are food for a variety of birds, and likely spiders as well. They’re harmless, unless you are a boxelder seed!”