When the several centimetres of snow covering most of Metro Vancouver lawns melts away, many residents will be reminded once again of the pesky European chafer beetle.
The invasive species began wreaking havoc in the region two years ago by infiltrating grassy turf and beckoning predators like raccoons and birds to come digging. By the time chilly temperatures rolled into the Lower Mainland in December, lawns were dug up and left ravaged.
Anyone hoping the sub-zero temperatures experienced over the last several weeks might have killed off the chafer beetle will be disappointed come spring.
Allan Carroll, a professor of insect ecology at UBC, says that while cold weather can kill off certain insects, the chafer beetle is quick to adapt.
“Species that frequently encounter cold usually will evolve some trait that helps them survive. In the case of the European chafer beetle, they apparently will burrow deeper into the soil to avoid cold,” Carroll said.
The good news is that the cold snap has probably killed some of the juvenile beetles, but enough would be able to survive to carry on the species.
“As a result, we may see a short-term decline in damage to lawns, but it is unlikely that the problem has gone away.”
When spring comes, Vancouverites will be back attempting to evict the beetle and its larvae from lawns. Many have tried nematodes – microscopic roundworms that kill the grubs of the European chafer beetle.