New York State IPM Program

June 1, 2018
by Mary M. Woodsen
Comments Off on The low-down on ticks. Part 1A, Biology Q&A

The low-down on ticks. Part 1A, Biology Q&A

Ticked off about ticks? You are not alone. And knowing the what, where, why, etc. is critical to knowing how to deal with them. So here it is, the first in a series: the low-down on that pest we love to hate.

May you, dear reader, stay tick-free and healthy.

1. What, exactly, is a tick?

Ticks are related to mites and spiders—but not to insects. (Now don’t go worrying about spiders—in the Northeast, virtually all are common victims of common misunderstandings.) Ticks have four life stages: egg, larvae, nymph and adult. All stages (well, not the eggs) feed on blood for energy to grow and later to reproduce. Larval ticks have six legs; nymphs and adults have eight.

Those things that look like antenna? Not—they’re highly adapted legs that process vital information. And that snout in the middle? Blood-sucking mouthparts. (Photo CDC)

Right now, three species are a health concern here in New York: the blacklegged tick, the lone star tick, and the American dog tick.

2. What do ticks look like?

Regardless the species, unfed ticks look like flattened teardrops with eight legs. And depending on their species, life stage and sex (male versus female), they have different color patterns on their bodies. But after they’ve eaten, their abdomens (the females’ especially) can expand so much that it’s really hard to know which is which. You can get positive IDs here.

Just keep in mind that learning a tick’s identity doesn’t mean you know if it’s carrying a disease.

I wrote a sentence on my finger, period and all. And yep, the larvae are that small. (Courtesy Cal Dept Public Health)

As for size? Again, that depends on the species, its life stage, and whether it has fed (and for how long). For blacklegged and lone star ticks, larvae are the size of the period at the end of this sentence. Nymphs? Think poppy seeds. Adults? Sesame seeds. When fully fed, adult females can be as large as a raisin.

American dog ticks, though, are a tad larger than the other two.

3. Are ticks a new problem? Why have we been hearing so much more about them lately?

Turns out ticks are nothing new. In fact, evidence suggests that ticks were carrying Lyme disease pathogens 15 to 20 million years ago (Lyme Disease’s Possible Bacterial Predecessor Found in Ancient Tick). What is new? We’re seeing far more ticks throughout the Northeast and much of North America than during any time in recorded history. And of course the more ticks in the neighborhood, the greater our risk of disease.

Why are ticks on the move? For one, (sub)urban sprawl leaves small patches of wooded areas—great habitat for mice and deer but far less welcoming to their traditional enemies—hawks or foxes, cougars or wolves. (More later on the role of mice and deer in tick-borne diseases.) In addition, a warming climate makes northern areas more hospitable for ticks.

Ah, yes. A place to call home—and nary a wolf in sight. (Photo provided.)

4. Where do ticks live? How do they find me? And where did the deer ticks go?

Blacklegged ticks are usually found in woodlots, forest edges, and groundcovers such as pachysandra or periwinkle—places where leaf litter, shrubs, and tree cover provide the moist environment they need. And how do they find us? Just as we sometimes go on quests, so too do they. Only they’re not seeking adventure or the Holy Grail, but simply a host. A host that provides the food (think blood) they need to thrive, or at least survive.

About deer ticks? Years ago, researchers thought they’d found a new species and gave it the common name “deer tick.” Turned out it was the same old blacklegged tick that’s been here since time immemorial.

No matter that these ticks lack eyes—questing ticks stand on the edge of a twig or leaf, their first pair of legs extended. Evolution endowed them with cleverly designed legs: they’ve got sensors to detect temperature, the carbon dioxide those hosts exhale, and odors or sounds specific to those hosts. When a host brushes past, they grab on tight.

The nymphs typically quest below a person’s knee-height. Because adult ticks feed on larger animals, they might quest higher up to find a host—as high as your waist-height or mine.

The lone star tick is on a roll, with its own suite of diseases and syndromes — some still mysterious. (Photo CDC)

The lone star tick thrives in a wide range of habitats, from shady forests to sunny lawns or roadsides. Unlike the blacklegged tick, the lone star tick hustles toward its prey, even across pavement or dry sand. Other distinguishing features? Well … it’s lots more aggressive. Imagine a tick that travels three times as fast as the blacklegged tick, has excellent vision, and hatches in stinging swarms that can put fire ants to shame.

Last but not least—the American dog tick. Forget the woods: this tick thrives in warm, dry places—roadsides, grassy fields, scrubland and lawns. Larvae and nymphs mostly feed on small mammals, while adults climb grass, brush, or twigs to find medium-sized animals—people included. And sometimes American dog ticks could be even more aggressive. TickEncounter has reported seeing American dog ticks follow a regular source of carbon dioxide that attracted them for upward a few hundred yards to the house. And in one memorable case ticks were crawling up the outside walls toward window screens and doors. Now if that doesn’t give you the willies….

No matter which tick you might collide with—this is one party you don’t want to host.

Stay tuned for another informative post on the biology behind that pest we love to hate.

(Adapted from nysipm.cornell.edu/whats-bugging-you/ticks/tick-faqs#answers)

April 27, 2018
by Mary M. Woodsen
Comments Off on The New Tick in Town (Part ll.)

The New Tick in Town (Part ll.)

Now for the science-y part of this post. (I suggest you re-read Part l. Can’t hurt. Might help.)

If you’ve read our other posts on the blacklegged tick (aka the deer tick), you might guess—and rightly so—that it’s the tick that’s been on our radar the longest; the one we (still) give most of our time and attention to. And all for good reason.

Sheer numbers (how much Lyme disease we’ve seen; what the co-infections are and how commonplace they are; its reputation as the “great imitator”) keep the blacklegged tick in the spotlight. Meanwhile, with the exception of Long Island, the lone star tick is rarely seen in the metro New York area and points north. But it has colonized some islands off Connecticut and established a toehold on Cape Cod in Massachusetts.

The lone star tick is on a roll, with its own suite of diseases and syndromes, some still mysterious. (Credit CDC)

Indeed, the lone star tick’s potential for harm could, somewhere down the pike, become a force all northerners face.

And consider this: though deer serve as a great food source and taxi service for ticks, they are immune to Lyme disease. Not so with the lone star tick. Because given the right circumstances, it can kill even deer.

So … what diseases or conditions does this tick carry—and could any be fatal to people? Here’s the short list:

  • Ehrlichiosis is nasty. Upward of two percent of those who get it might die.
  • Tularemia is nasty too, though less so than ehrlichiosis.
  • Heartland virus is rare—and most people who do get it have mild symptoms; perhaps none at all. But yes, some will die.
  • Alpha-gal syndrome? Perhaps—especially if you don’t know it for what it is. While the symptoms can be frighteningly intense, not everyone reacts with that same level of intensity. Plus this syndrome’s transcontinental spread in places lacking lone star ticks leads to yet-unanswered questions.

Ouch! Lone star ticks attach quickly—and some people react quickly. Sometimes it looks like this. (Credit: Copyright © 2015 American Medical Association)

So how about STARI, or southern tick-associated rash illness—can it do you in? My careful search turned up zilch, zip, zero. Doesn’t mean STARI won’t send you to an early grave. But if it could, I can’t find credentialed scientific sources to back up such a claim. You’ll be interested to know, though, that the rash STARI stands for can, on the surface of things, make you think you might have Lyme disease. And more unanswered questions: as of August 2017, the pathogen that causes STARI remains unknown.

 

 

 

Sources:

 

 

 

June 16, 2017
by Mary M. Woodsen
Comments Off on Tick Trickery and Lyme Disease: the Great Imitator? Sometimes.

Tick Trickery and Lyme Disease: the Great Imitator? Sometimes.

Remember the days when we could play with our tykes in tall grass near a wooded hedgerow? When we could wander at will through open meadows, picking wildflowers? When we could have impromptu picnics in the shade of tall oaks and basswoods deep in wild violets and leaf litter where a park blended into a tennis court, say, or a golf course rough? (Here, “rough” is a technical term used by the golf literati.)

Those days are gone. Now people in the Northeast and upper Midwest who live near anything green also live in a world that — subjectively at least — seems dominated by ticks. Blacklegged ticks (aka deer ticks) especially come to mind, but others are coming down the pike. (Lone star tick, anyone?)

The Southeast, eastern Texas, and the Pacific coast likewise see blacklegged ticks setting up shop.

Now — and remember this before you freak out — by no means does every tick vector Lyme disease or any of its coinfections, including anaplasmosis, babesiosis, and Powassan virus. The Centers for Disease Control (CDC) and National Institutes of Health (NIH) have a bountiful supply of carefully researched  information on these diseases.

CDC and NIH also keep tabs on long-term effects of Lyme — for instance, complications  like Lyme carditis and Lyme encephalopathy — that are important to understand.

And because Lyme can also mimic a considerable range of diseases — many less than pleasant — NIH and PubMed (the website is admittedly a bit of a slog) fund a considerable amount of research on these sorts of things.

Researchers might find, for instance, that what appeared to be ALS was actually  Lyme — for this patient, surely an enormous relief. A course of antibiotics and it was over. But if you find websites that link Lyme with upward of 300 diseases, best be skeptical until you can confirm the  science behind the claims that interest you most.

So let’s circle back to where we began.  Yes, you can still get your fill of nature. You can still hang out in your yard. You just need to know some basics. Prevention, in a word. That IPM mantra.

Prevent — well, most of us especially want to know how to keep those little buggers off us. So … how then? Well, consider the permethrin route. Permethrin is synthesized from a compound — pyrethrin — found in the seed cases of chrysanthemums. (Know that many plants include toxins to a lesser or greater degree — it’s the nature of nature. But that’s a whole other post.)

So take a hike over to Tick Encounter and learn all about treating your clothes, your shoes, whatever, with permethrin. Other search terms for permethrin, whether at Tick Encounter or elsewhere, might include “treat backpacks, tents, ground cloths …” You get the idea. But please — keep your antennae tuned for potentially bogus claims.

Want to learn everything you can about the ecology and biology behind ticks and Lyme disease? The Cary Institute for Ecosystem Studies is where you belong.

And if you’re perplexed by where “blacklegged tick” comes from when “deer tick” seemed to say it all — well, it’s worth knowing that deer aren’t the reservoir hosts; they don’t carry Lyme. Essentially it was a case of mistaken identity. Back in the day, when Lyme first erupted, researchers thought they’d discovered a tick new to North America; its common name became “deer tick.” A few years later scientists discovered that this deer tick was none other than the already-known blacklegged tick. There you have it and so it remains.

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