Norway is projected to have growth in ticks and new tick species because of climate change (warmer and more humid climate), so that's one example of it moving north (though ticks seem to always have been in Norway?)

Sweden appear to have the same trajectory: https://www.svt.se/nyheter/sapmi/fastingar-finns-nu-over-hel... (run article through your translator of choice)

They don’t like heat? That seems incorrect. If true, Then why are they a huge problem in TX and other southerly areas, and are only now spreading north?

Different species I belive. Ticks in Texas are differnent from ticks in Ottowa. Most lyme disease in the US is concentrated in the northeast and northern great lakes states and into Canada (though it is spreading over the past few decades).

https://www.cdc.gov/lyme/data-research/facts-stats/lyme-dise...

Correct.

Texas has the 'Lone star Tick' primarily. But in Michigan for example we've had the Blacklegged tick (which is the main species known to carry Lyme in our state...) for a looong time.

They seem to be much less active on hot days compared to cooler days in my experience - though I can't say why. I've definitely observed a difference over the years though.

That said, whether it is hotter or cooler doesn't make much of a difference in terms of how you go about your day - you pretty much have to assume you can encounter them regardless.

They are a huge problem in Minnesota as well.

It's the length and depth of cold days in the winter that can potentially limit their breeding populations, is my understanding. So the issue is that more northerly areas are getting much more variance in temperature and lacking long deep consistent cold periods.

Up and down cycles in temperature have always been a thing on the North American continent but climate change has made it even more variable. We will still get places where it gets very very cold but not for the consistent chunks of time it takes to set back tick populations significantly.

TLDR I don't think it's the heat or cold per se but the variance.

And yes climate change is absolutely the prime factor in their spread. Into places where they were not ever a threat before.

> So the issue is that more northerly areas are getting much more variance in temperature and lacking long deep consistent cold periods.

It impacts the population, but even a couple solid weeks of -20C weather doesn't seem to be enough to eradicate them.

Ticks have always been around Ottawa, and even in 2011? I recall -40C for well over a week, and obviously cold temps around that week.

Insects lay eggs, and also go dormant under fallen leaves typically. The snow + leaves insulates them, it's how live insects survive the winter.

If you watch robins in the spring, before the ground thaws, you'll see them flipping over leaves. They're eating loads of insects hiding, most still torpid from the cold.

-40C isn't a problem for ticks to live through in this way.

In terms of population, everything follows predator/prey cycles. Nothing is static. It's normal for populations to "explode", eventually predators will grow in numbers too.

I see it with noseeums here, and dragonflies. There are almost no noseeums this year, but loads of dragonflies, which means the dragonfly population will collapse, and soon (couple of years) the noseemums will be relentless. But then the dragonflies will grow in numbers, with plentiful food, and the cycle will repeat.

It's natural.

Global warming may shift habitats, but these ticks are normally here. They're not new.

The lowest recorded temperature in Ottawa in the last 40 years was -33.1c in 1996. It hasn't been down to -40 since like 1911.

You might be recalling wind chill temperatures, which would not be relevant here. They're subjective perceived temperatures for hairless apes.

However it does occasionally get to (real) -40C ish in Edmonton area, and they now have populations of blacklegged ticks. But very small populations.

Like I said above, the issue is not the absolute lows or highs, it's durations of cold, which impact their ability to recover and produce large quantities of eggs in the spring. This was literally in an article I was reading about ticks the other day, don't make me hunt for it.

Black legged ticks are not new to Ontario, but they absolutely are to places like central Alberta. And the Lone Star tick is moving north for similar reasons and will be established here in Ontario shortly as well.

I live in the Ottawa region, and it was indeed -40C for a week where I live. My Jetta screaming "warning extreme cold!" at start, and the kitchen window thermometer I have doubly validate that.

I'm also 20 minutes to downtown, outside of rush hour, so I stand by the ease of saying "Ottawa".

No you don't get my address, but temperatures in cities and at airports are warmer than rural areas in winter. Where I live, I'm also higher up by several hundred feet, and it all matters. I don't blame you for checking, but the city of Ottawa encompasses a lot of rural land.

It can rain torrents in part of southern Ottawa, but Ottawa weather stations could remain dry.

My point about snow and leaves, is that if there is snow cover, they're completely happy, insulated, nestled in the leaves.

I don't doubt you read an article, and from a reputable source, I just don't buy their assertions. Lack of snow cover would be a bigger predictor than overall temp.

Dude, weather stations record actual temperatures both in and outside the city. Environment Canada peppers the whole province with them. There's nowhere in southern or eastern Ontario that gets as cold as -40C. It simply doesn't happen. -35C is the lower bound and that is extreme.

I know this because I farm and grow grapes and have meticulously poured over weather charts for the whole province. (Survival cut off for hybrid and wild grapes is really around -32C or so. Vinifera... maybe -20C)

And yet, it was colder than -40C.

I think you believe temperatures are far more homogeneous than they are. On my way home, 500M of road over a hill makes 35C turn into 31C.

And no, weather stations aren't everywhere. I think the nearest one is 20km away.

If there was more diversity in predators and prey, the population cycles would have smaller amplitudes. The large swings are often symptoms of a collapsing ecosystem.

I’ve seen a tick in Wisconsin every month of the year over the past five years or so. That is I’ve seen a January tick one year, February tick that same year or another year, etc. Whenever there is a bit of a warm spell they appear. Presumably small upward trends in temperature allows such warm spells to happen more frequently.

I think it's that they need humidity or else they dry out. So hot and humid is fine. Hot and arid is what they have a problem with.

Ottawa summers are hot and very humid but the ticks disappear during that season.

The black-legged tick season in Ottawa is March through June and again September through November. Summer (deerfly season) is just too hot for them and they go to ground.

We do all the best camping in January and February. Why, you might ask, when it's usually colder than -20 C? No ticks. Also no mosquitos, blackflies, or deerflies but mostly no ticks.

AFAIK there was a Lyme disease vaccine, but was discontinued, probably because it wasn't effective enough, I don't remember the details.

TL;DR; antivaxers

Nope.

This is key paragraph from the link:

> The effects of vaccination on human behaviour presented yet another important uncertainty. Lyme vaccination, although it provides incomplete protection, may make individuals less likely to limit their exposure to ticks, which might actually increase their risk of Lyme and other tick-borne diseases (e.g. ehrlichiosis, babesiosis and Rocky Mountain spotted fever).

That was a very half-assed attempt. Hopefully a better one is coming soon.

That's one consideration of a possible issue, not a key reason it was retracted

The "cautionary" part of the cautionary tale referred to in the article title is that a working vaccine was retracted mainly due to unfounded fears

e.g from the article summary "Just 3 years later, the manufacturer voluntarily withdrew its product from the market amidst media coverage, fears of vaccine side-effects, and declining sales. This paper reviews these events in detail and focuses on the public communication of risks and benefits of the Lyme vaccine and important lessons learned."

The "public communication of risks" not the actual risks.

There has been a vaccine for dogs and cats for a while now, not sure why it hasn't been released for humans yet. Lyme can be really horrible. Some people we know have a 30-something son who was very active (camping, hiking, rock climbing, etc.) until he was bitten by a tick. Now he's quadriplegic.

Lots of drugs work for dogs and cats because they don't live longer than 25yrs. A human has 3-4x the lifespan during which side effects can be worse than the disease.

Is that true? I don't know of really any medicine that has side effects 25 years down the line. Would we even know? We don't test new meds that long before release.

Isn't it more because meds are cheaper to test on animals and liability is much lower?

When I asked why there is no human equivalent of flea/tick drops my vet said it was because "when you only live to be 20, you don't worry about smoking when you are 10."

I think the original, mouse brain derived Japanese Enephilitis vaccine, now discontinued, caused symptoms years later.

But prions were the cause, and those are slow acting.

The new, safer vaccine is only recommended if you're going to Japan or surrounding areas, and planning to going outside the city.

Typically because it's rare enough that the cost/side-effect risk of the vaccine isn't judged to be worth it.

Humans generally aren't vaccinated for Rabies either, unless you are e.g. a veterinarian who might have a higher chance of exposure to it.

Encephalitis is much more rare, but it's much worse than lyme. And there's a stab for it. Meanwhile Lyme is much more common, but much simplier to treat. Which is basically „take antibiotics or 3 to 21 days“ depending on how long it's been since the bite.

What is an "encephalitis stab"?

In my whereabouts tick-born encephalitis is a much bigger issue. But thankfully vaccine for it exists.

So there's no natural immunity after having it once? How would a vaccine work then?

There are many strains. You will develop immunity to one strain, but not the others.

I assume a vaccine would try to be multivalent.

Even for the specific strain, it's not long-lived and strong enough.

“Lyme” colloquially covers half a dozen to a dozen different bacterial infections.

"Lymne" refers to an infection by the spirochete Borrelia burgdorferi, a bacteria closely related to syphillis. There are plenty of other tick-borne diseases (including localized staph infections at bite sites that can lead to necrotizing fasciitis)

Just like with syphillis, there is a cheap and simple cure that is more effective than any known vaccine. If it's caught in time. Prevention is even cheaper.

The standard treatment for Lyme also just happens to be the standard treatment for many of the other tick-borne diseases, so you're still better-off taking a course of doxycycline after a tick byte than getting a vaccination against Lyme.

> Lymne" refers to an infection by the spirochete Borrelia burgdorferi

There are also common coinfections which are grouped under the same name, despite being unique.

IIRC there's no immunity. Or at least it's gone after some time.

I don't understand why we're not vaccinating deer populations, even if we're not vaccinating humans out of safety concerns, etc.

That and deer populations need to be significantly culled (along with rodents, the other part of the Lyme / deer tick population cycle).

In any case, lack of long consistent extended cold spells in the winter to set back their breeding population is the reason they've moving further north. Which is tied directly to climate change.

I believe mice are the main host of tick populations

The black legged tick has a complicated lifecycle which includes both rodents and deer (or other large mammals I believe)

Clearly we should be banning all rodent/deer contact until the tick population is under control.

cmrdporcupine says "I don't understand why we're not vaccinating deer populations, even if we're not vaccinating humans out of safety concerns, etc.

That and deer populations need to be significantly culled (along with rodents, the other part of the Lyme / deer tick population cycle)."

Yep, we should extend the deer hunting seasons so we can vaccinate 'em with lead (I'll leave the rat hunting to others).

Rodent populations are notoriously hard to control. But it seems that a deer cull would be easy. I am surprisec that they are not done.

> Ticks are a problem regardless.

Ticks in my part of the world were never such a large problem. It was rare that you'd get one on your leg in the field behind our house, and now, you literally can't walk through the grass each year without having 10+ on your legs in a matter of minutes. Warmer and wetter weather and fewer hard winters. The presence of Lyme disease has also increased in them.

I have direct experience of this, so downvote all you want, climate change deniers.

In my whereabouts ticks were common 70+ years ago too. But nobody seemed to give a damn about them since disease-carrying ticks were not a problem. Talking to my grandma, it was common to have ticks in her youth. But now a massive chunk of them is lyme or encephalitis carrying. And suddenly it did become a problem ~ 20-30 years ago.