Tick news.

The Public Health Agency of Canada (PHAC) reported 5,809 confirmed Lyme cases in 2024 — a national rate of 14.1 per 100,000. Ontario leads in absolute counts; Nova Scotia leads per capita. See the numbers by province, month, and age.

Blacklegged tick nymphs — the life stage responsible for most Canadian Lyme cases — are at peak activity from late April through June in southern Ontario, southern Quebec, southern Manitoba, and the Maritimes. PHAC’s risk maps continue to expand year over year; areas that weren’t classified as Lyme risk zones five years ago often are now.

If you spend time in long grass, leaf litter, or forest edges anywhere in those regions this spring, assume blacklegged ticks are present. Daily tick checks during May and June catch the overwhelming majority of bites before the 24-hour transmission window closes.

The Lone Star tick (Amblyomma americanum) — identifiable by the single bright white dot in the centre of an adult female’s back — has expanded its established range in southwestern Ontario over the past several seasons. Sporadic individuals have been recorded further north, almost certainly arriving on migratory birds.

Lone Stars are aggressive biters and the primary North American vector for alpha-gal syndrome — a delayed allergic reaction to red meat that develops after repeated bites. Canadian cases remain rare but the trend is worth tracking. Any tick with a clear white central dot is worth submitting to eTick.

eTick.ca, run by Bishop’s University, is a Canadian site where the public submits tick photos for expert identification. Submissions are free, you usually get an answer within a few days, and your submissions help Health Canada track where ticks are spreading.

If you remove a tick, photograph it (or save it on a card) and submit through etick.ca. You’ll get the species back and help everyone else understand what’s out there.