Ladybugs are often associated with the arrival of spring, but with the arrival of cooler weather and the impending winter, don’t be surprised if you start seeing more spotted beetles than usual.
Brian Spencer, a microbiologist and president of Applied Bio-nomics Ltd. in North Saanich, says the invasive ladybug species commonly known as the multicoloured Asian lady beetle is in the process of hibernating.
“Like most beetles they have a winter congregation pattern. Sometimes they appear on the south side of a house year after year, sometimes they pick different houses,” Spencer said. “They also tend to find a way to get into people’s houses. They want to, over winter, be in your kitchen. They’re looking for a nice, warm place to spend the winter without freezing to death.”
Spencer says this species of ladybug was released in the 1970s in Georgia and has since swept across North America.
While the multicoloured Asian lady beetles aren’t native to the continent, they do play a role in controlling the aphid population in the spring and summer.
“There’s a bit of concern that they may displace our native ladybug species. (Native ladybugs) hibernate up in the mountains on the Malahat and climb under rocks. (Multicoloured Asian lady beetles) like structures better than rocks, and because of that their congregation pattern is more noticeable for us,” Spencer added.
The multicoloured Asian lady beetle is not the same ladybug species that local municipalities – Saanich and Victoria included – release to eat aphids. Those are the convergent lady beetles.
Cory Manton, Saanich’s manager of urban forestry, horticulture and natural areas, says they release convergent lady beetles on a handful of streets in the spring.
“We don’t have the same aphid issues as the city. We don’t have the monoculture-type species planting on developed boulevards that they have,” he said of trees that attract aphids, like linden, beech and some invasive oaks.
Spencer says the multicoloured Asian lady beetle is here, whether we want it or not and its numbers are building.
If you find ladybugs in your home this fall or winter, try to move them to a cool area like a garage. Spencer warns about reflex bleeding if you try to brush them away, so he suggests vacuuming them into a bag, leaving them for the winter and then dumping them in the garden come spring.
kslavin@saanichnews.com