Experts say this year’s snowy winter will not hinder the tick population

If you were hoping that Nova Scotia’s relatively snowy winter would mean fewer ticks this year, experts warn you might be disappointed.

Tick ​​researchers say deep and long-lasting snow may actually be a help to these hardy insects, not a hindrance.

“That deep snow cover is really providing a huge layer of insulation for them,” said Laura Ferguson, assistant professor in Acadia University’s biology department. “So they have been preserved to a great extent.

“I’m hoping that maybe, you know, we have such a large population of ticks that a good portion of them have been here this winter and we’ll see them here again soon.”

CBC meteorologist Ryan Snowdon said that while Nova Scotia had some cold snaps in December and the first half of January, our most sustained tick-killing temperatures came when there was already snow on the ground to protect them.

Halifax Airport experienced continuous snow on the ground from January 18 to March 21, a total of 64 days. This is the longest extension of snow cover at that location since the winter of 2020.

Ticks look for sheltered places such as under leaf litter to hide in the winter. They do not need to eat for months at a time, and in fact, in very cold climates their metabolism slows to such an extent that even if a salacious host – a bare human leg or a dog, for example – passes them by, they may be unable to move to take advantage of the opportunity.

Ferguson said ticks can survive for weeks or months in 0 C to -5 C weather. Persistent temperatures below -10 C without the protection of leaf litter or snow can cause death, as can sudden fluctuations in temperature.

If ice freezes inside their bodies, it can damage their tissues and kill them.

Jantina Toxopius is an associate professor in the Department of Biology at St. Francis Xavier University and is researching how temperature affects ticks.

Toxopius said they usually freeze at temperatures below -15 C, at least in a laboratory.

However, he said how quickly the temperature drops makes a difference. Like the proverbial frog in boiling water, they appear to be better able to adapt to slow changes.

“If it’s a shock, if it’s like a real quick temperature change, they seem to struggle,” Toxopius said. “But then we tried some slow ramps down to -10 C and they were actually fine.”

He said most people think extremely low temperatures will kill an insect, but ticks “deal with cold very well.”

Toxopius said that a few years ago, Nova Scotia had extremely cold temperatures of -27 degrees Celsius, but since then he has seen no decline in tick populations.

“So yes, the ticks are doing absolutely fine,” she said.

Ferguson said he doesn’t expect this year’s tick season to be any better or worse than past years.

“We’ve got a very strong, courageous population,” he said. “I think it will be more or less the same as it has been for the last several years.”

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