Swarms of invasive red and black bugs are taking over Ontario right now

If you've noticed masses of red and black bugs congregating outside of your Ontario home over the past few weeks, you're not alone. The pesky culprits, known as the European or red firebug (Pyrrhocoris apterus), are especially active this time of year, and dozens of sightings have already been reported across the province. 

Native to Europe and western Asia, the species was first recorded in North America in 2008 in Utah, and since then, its presence has spread rapidly. In recent years, it has become an increasingly common pest in Ontario, where residents regularly report large clusters of the bugs gathering on homes, trees, and other structures on the biodiversity social network, iNaturalist. 

Just this past week, dozens of sightings have been reported in Ontario and all over the GTA, including in Hamilton, Pickering, and Mississauga. 

Photo: catphish/iNaturalist. 

The red firebug is often mistaken for the Eastern box elder bug due to its similar red and black and colouring, however, unlike the latter, the red firebug has no impact on tree health and is not classified as a forest health concern, meaning municipalities, including the City of Toronto, do not provide any treatment or control services. 

Female red firebugs begin laying eggs in June, producing between 40 and 80 eggs over their lifetime. The nymphs then mature into adults within 17 to 24 days, and adults can live for up to two years. 

The bugs are most often seen in large clusters in the late summer and fall, when they begin seeking warm, sheltered areas to overwinter, meaning your home or building often provides ideal conditions.

Photo: shawnchong/iNaturalist.

Despite their somewhat alarming appearance and name, red firebugs don't pose a threat to humans, pets, or plants, and they primarily feed on fallen seeds, with linden trees being a common host in the GTA. 

If you come across one of these bugs, the last thing you'll want to do is crush or squish them. Red firebugs emit a foul odour and may stain carpets or fabrics when crushed, so you're best bet in avoiding the bugs is to take preventative measures, including sealing gaps around your windows and doors, repairing foundations, and making sure your screens are intact. 

Photo: ryan2775/iNaturalist.

If you've already been hit with an infestation, the City of Toronto recommends vacuuming as an effective removal method, as well as exterior insecticide treatments applied in the fall to siding, windows, and foundations.

Alternatives include using a high-pressure water hose to dislodge the insects from surfaces or using a DIY spray solution made from dish soap, cooking oil, and water to knock down the bugs.