The Bug Geek

Insects. Doing Science. Other awesome, geeky stuff.

Photo Friday – Deer Tick (Ixodes scapularis)

Lesson learned this week: people get really excited about parasites (holy page-hits, batman!!!) I’d already planned this post for today, but it fits nicely with the gross-out trend started on Wednesday.

A few days ago my wife was snuggling with Solomon, our fat, grouchy, old, outdoor boy-cat, when she felt a lump at the nape of his neck.  “Sol’s got a tick!” she announced. Ticks may not be as exotic as brain-bending beetle-banes, but they’re still pretty nasty (and therefore also cool).

I gleefully ran to get my tick tool, an ingenious little plastic do-dad that lets me literally twist a tenacious tick off the victim’s skin intact (leaving mouthparts embedded in skin can be bad news in terms of infection).  Fur was parted, tick scooped, twisted, and voila – off.

Usually Sol’s hitchhikers are common Dog Ticks (Dermacentor variabilis).  This one looked just a bit different.

tick 4_small

It is smaller than the ticks I usually see (this animal was about 6mm long), and the shape and color of the shield (the roundish area behind the head) were different. Also, see those super-long (creepy) palps?

After having done a bit of googling, I’m pretty sure that this is a Deer Tick (Ixodes scapularis), which is not particularly awesome, since they are known vectors of Lyme disease. The only other time I’ve seen this species was when I plucked a very tiny one off my wife’s leg after a walk in the woods. I brought it to our local health unit, and thankfully it tested negative.

A recent study of Deer Ticks collected from people’s pets in my home province (Ontario) showed that about 1 in 10 were infected with Borrelia burgdorferi , the bacteria actually responsible for the sometimes debilitating disease.

Results of tick-testing in Ontario, Canada, from 1993-2002

We live just to the east of that great big red circle by Kingston.  Although I am a teensy bit comforted by all the white dots closer to our area, I have to suspect that the range of Lyme-carriers has shifted eastward since these data were collected. (Eep.)

My wife’s reaction upon discovering this tick was, “Shouldn’t these be gone by now? It’s November!” While a lot of 6- and 8-legged critters are indeed out of commission for the winter by this time, mature Deer Ticks are most commonly found on pets in October and November. This is because the ticks are mostly in the larval stage during the warmest summer months of July-September. The larvae are incredibly tiny, not much bigger than the period at the end of this sentence, so they’re easily overlooked.

Although I’m not thrilled about having this species lurking around my home, I have to admit I was rather taken with one of its features. I didn’t notice this until I was processing my pictures:

Microsculpture of spiracle and side on Ixodes scapularis, the Deer tick

Mega-closeup of the tick's integument - cool!

This is an extreme closeup of a small area just above the spiracle (the little hole on its side through which oxygen enters its body). You can see what was turning my crank: the really cool sculpturing – all those little wavy lines on the upper regions, and the concentric circles around the spiracle. Sculpture (which is often visible to the naked eye), and even microsculpture (which usually requires a microscope to be seen), can be an incredibly useful tool when identifying insects to the species level.

———————————————————————————

ResearchBlogging.org

Morshed MG, Scott JD, Fernando K, Geddes G, McNabb A, Mak S, & Durden LA (2006). Distribution and characterization of Borrelia burgdorferi isolates from Ixodes scapularis and presence in mammalian hosts in Ontario, Canada. Journal of medical entomology, 43 (4), 762-73 PMID: 16892637

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11 responses to “Photo Friday – Deer Tick (Ixodes scapularis)

  1. Katie December 2, 2011 at 10:01 AM

    Love your macro shots! Invert parasites are fun to read about, but not so much fun in person. As I was plowing through my BS in Entomology, we obediently spent a couple lectures with vials of bed bugs attached to our wrists to document the Jones-Mote levels of hypersensitivity. And, then I unwisely chose the same wacky medical Entomology professor to be my honors research advisor and ended up needing to feed a colony of rather large tropical mosquitoes with my own blood. I think my Calculus and Latin Women in Literature grades faltered a bit as I spent too many sleepless nights in itchy discomfort. I very quickly realized that I didn’t want to research anything that sucked blood. Lyme disease is not to be trifled with. Unfortunately, there are few doctors here in the US that know how to recognize or even treat the disease effectively. Am wondering, do animals get Lyme disease symptoms like humans? It looks like yours fully engorged on your cat. Thankfully it tested negative.

    • TGIQ December 2, 2011 at 10:17 AM

      Yeah, they’re pretty icky 😛 (Whoops, totally missed the rest of your comment!) I know for sure that dogs can get it and suffer the same kinds of ill effects as humans. I’m not sure about cats, but I suspect if it’s transmissible to dogs the same applies for the kitties. The one I tested negative was on my wife, not my cat; this one did not get tested (it, um, disappeared on me o_O)…it was also not quite fully engorged but close. I get the animals checked pretty regularly for baddies (intestinal/blood-borne parasites) so fingers crossed that we’re ok with this one too. I imagine that there are many other ticks that I DON’T see.

  2. Morgan Jackson December 2, 2011 at 11:04 AM

    Blegh. Sweet photos of a creepy-ass subject!

    • TGIQ December 2, 2011 at 11:38 AM

      Yeah, they creep me out…but sort of in a good way? Is that wrong?

      • Morgan Jackson December 2, 2011 at 12:22 PM

        Well the sculpturing is pretty cool, I had never seen that before (probably because I’m usually running the opposite way at first sight), and I imagine that’s a function of their amazing expanding act, so I guess the creepy is cool in its own way!

        • TGIQ December 2, 2011 at 12:25 PM

          I was thinking it looked rather accordion-like…makes me want to find a teeny one and see if it’s REALLY wrinkly. Sort of 😛

          • Alex Webb December 2, 2011 at 12:29 PM

            Excellent post! At first I thought the close up with the spiracle contained some kind of parasitic worm and I thought we were going for a double parasite post. Sigh. Maybe for Christmas. Still, loved your shots, and good reading, too!

            • TGIQ December 2, 2011 at 12:33 PM

              Sorry to disappoint, Alex…it was just a random fluffy that I neglected to remove before taking the picture. Wouldn’t that have been AWESOME though??? I’ll see what I can do cor Christmas 😀

          • Morgan Jackson December 2, 2011 at 12:34 PM

            LOL now all I can think of is a tick turned into some sort of weird, miniature set of bagpipes! Just need to trim those tarsomeres back a bit, and you’re all ready for the Grassland Games!

  3. tickstransmit December 2, 2011 at 5:24 PM

    Fortunately the tick found on your wife tested negative…for Borrelia Burgdorferi (because that is the only pathogen that the Public Health dept’s/Labs test ticks for) UNFORTUNATELY, there are about 8 pathogens that can be transmitted by ticks….and ALL ticks can transmit pathogens. So the next time that tick is found on a person – please don’t be so quick to sigh that sigh of relief because it tested “negative”….and if your lovely “Tom” is bringing ticks in – please educate yourself on the symptoms of infections of these other possible diseases.
    Wishing you good health.

  4. Endless Swarm December 8, 2011 at 12:28 PM

    I think ticks are rather attractive, and I love the macro of its integument! Don’t get me wrong, having them crawl on me still gives me the shivers, but I can’t help being entranced by their awesomeness. I think I started to appreciate Ixodids when a friend in Costa Rica sent me a selection from his research station (entombed in packing tape). It was like a collection of miniature African shields! So neat.

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