Pardon the mess

I finally got fed up with the lack of SSL certificate for this site, so I decided to switch hosting providers this morning. Predictably, the move caused many of the pages to mutate to different URLs and some of the images to disappear. And my viewer statistics have forgotten that I had almost 3 million views. It’s going to take me a few days to fix everything, but I’m on it. In the meantime, please at least enjoy my Secure Sockets Layer. I know, pretty exciting.

ssl

I also took the opportunity to give my blog a name: Wunderkammera. I like it a lot more than “Colin Purrington’s blog”, which always sounded like I was hawking cat toys. Not that there’s anything wrong with that. If you’re curious what wunderkammera means, please see the About page. If the link still works.

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Beech blight aphids attacking spider

Here’s a spider being attacked by beech blight aphids (Grylloprociphilus imbricator). The spider eventually dropped off the tree trunk onto the forest floor and crawled away, twitching slightly. This is a known defensive behavior of the aphids, but I’d never seen it before. Apparently the stylets are sharp enough to puncture human skin, too. Wish I’d managed to get better photographs, of course.

Beech blight aphid (Grylloprociphilus imbricator) attacking a spider

Clayton Park, Monmouth County, New Jersey, United States.

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Bats with red spots

During a 2008 trip to La Selva Biological Station in Costa Rica, I took a terrible photograph of some lesser sac-winged bats (Saccopteryx leptura) roosting on the underside of a tree.

Roosting bats covered with red dots

I kept the photograph because the bats seemed to sporting some strange red dots that were the color of giant red velvet or trombidium mites, and I was curious. But I looked online (for years) and for the life of me couldn’t find any reports of something that large on a bat in Costa Rica. All I succeeded in discovering was that quite a few smaller mites seem to be found on bats (Banks 1915; Klimpel and Mehlhorn 2013), with new species found all the time.

One person suggested that they might be chigger mites (Trombiculidae). Each spot, perhaps, would be composed of hundreds of mites feeding together. Chiggers feeding in a group isn’t rare, apparently. If you search for “trombiculidae aggregation” you’ll get lots of images of seething groups (e.g.) on all variety of animals. But it begs two questions. Why does each bat have only one clump, and of the same size.

UPDATE: After posting and sharing on Twitter, Sean McCann sent me a message asking whether my dots might be marking bands. He also sent a photograph (a good one) in which the locations of the bands exactly matched where my dots are in my photograph. So I contacted Dr Carlos de la Rosa, the Director at La Selva Biological Station, to see if anyone was banding bats at the time, and he responded that it was likely … and is checking to see exactly who. I’ll post an update if I hear back. 

UPDATE II: Dr de la Rosa spoke with Dr Martina Nagy, who claimed those bats as part of her research (as well as corrected my species identification; they are not rhinoceros bats). She even recognized the tree (“SOR 170 Sendero Oriental”). These individuals (two males, one female) had been banded by Dr Barbara Caspers. The tree eventually fell and then the bats disbanded to someplace else. 

It took me almost 10 years, but I’m glad I finally know what was going on. That photograph had really been bugging me. Thanks, everyone!

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Shaving your legs to deter ticks

Colin Purrington Photography: Green steps &emdash; girl-with-shaved-legslook younger (artificial neoteny), to look less like men, to show off tattoos, to show off muscle definition, to improve athletic performance (less drag, plus fools brain into thinking you’re going fast), to facilitate post-accident wound cleaning (cyclists), and because shaved legs induces a pleasurable sensory overload (at least to some). But can shaving also protect you from ticks? I became curious this week after watching a tick crawl up my leg (photograph below). I was really surprised to discover that no experiments on this topic have been done, but did succeed in finding three relevant snippets on the internet (two from mountain bikers, one from cross country runner):

“One thing that helps is shaving your legs. Not a foolproof way but I would say it reduces them critters by 80%, maybe more. I noticed that when my wife and I were out and she had none, I had around 14 that day.” source

“As an experiment I shaved my legs before riding point to point at lbl with KRS and a few others. It was tick season. After 40+ miles of riding I had 1 tick on my sock. Along the way KRS pulled OVER 15 ticks. We rode the same route at the same pace. I’ve kept the hair off ever since.”  source

“I’d say its mostly impractical. Although, I know many trail runners (including myself sometimes in the summer) do it to prevent ticks from attaching.” source

But, hey, maybe the anecdotes are just that, and hairy legs actually deter ticks in some way.

Colin Purrington Photography: Spiders and ticks &emdash; American dog tick (Dermacentor variabilis)

But it makes sense that shaving would deter ticks. The first is obvious: ticks can grip hair, so if you are hairless (and are wearing shorts, skirt, or kilt), they can’t climb as fast (they are headed for your groin, by the way). The second is that you if you have hairless legs you can most likely better feel them crawling up your legs. I.e., all eight of their legs are touching your skin’s sensory array (or all six of their legs if they are larvae). The third is that when you remove all your leg hair you are removing a lot of sensory distractions caused by wind (experiment on swimmers), and thus you can zero in on things crawling on you. Indeed, all of these mechanisms might touch on why we evolved to be relatively hairless in the first place.

So about the experiments that need to be done …

An easy way to assess would be to count numbers of ticks on a group of people out for a walk, some of whom shave. But at least in the United States, that would break down to men versus women, and males smell worse than women and thus might attract more ticks, regardless of hirsuteness. And men are usually larger, so there’s the surface area thing that goes against us, too. So it would be far better to recruit a group of hairy-legged women and ask them to shave just one leg, then march around a field known to have ticks. Participants would tie white bandanas around their upper thighs to arrest the ticks before they got too intimate, then count tick numbers. But finding enough women who don’t shave might make the protocol hard to follow (again, at least in the United States). So perhaps using a group of guys would be more feasible. An ideal group might be a men’s college swim team right before the season begins. Just ask the coach to donate their legs for science. Would be an easy publication for a day’s work, and the experiment would be crazy photogenic. Plus great team-building exercise. Would get the college on the evening news I’m sure.

A simpler design might be to just have a motivated group of people (perhaps students in a field ecology course?) conduct tick races on shaved, unshaved legs. You just need to start them on the ankles and have participants hold still while the ticks make their ascents. That would be equally photogenic and fun, I think. And to get at the perception part, you could have blindfolded participants that would be asked to identify location of ticks crawling up legs (with controls being placement of non-ticks on ankles, perhaps).

The proposed experiments might seem horrific, but just the for record, I once swam around the edges of a small pond just to see how many leeches would attach to me. I recall that my father challenged me, and that we were going to see who could win. I don’t remember who ended up with more. (Yes, that was a nerd x testosterone interaction effect.)

If somebody does go ahead and conducts this experiment — and if the effect is huge (my guess) — the next step would be to alert the folks at the CDC so they could add a shaving recommendation to their tick page. The reaction to that would be entertaining.

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Conference poster full of tips for creating conference posters

In case you need a quick guide to making a conference poster, here are two versions of my poster of poster tips. They have content overlap, so just choose the layout that pleases you. More details below the images.

Poster example (Colin Purrington's)Advice on designing scientific posters

Both posters are descendants of a document I created circa 1997 for my evolution students at Swarthmore College. The bottom one is available as a PDF if you want to print an actual poster of it — which I highly recommend if you are assigning a poster project for your class (students don’t like reading the website, below).

My full tips are at Designing conference posters. I created the website for my students, too, but eventually made it public in case it might help make the world’s poster sessions more enjoyable and their posters easier to understand. Please share with your friends.

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Pyractomena borealis mouthparts

Here are four anterior close-ups Pyractomena borealis. The telescoping head allows the larva to inject (via curved, hollow mandibles) a numbing agent into snails that have retreated inside their shells. The antennae and maxillae are also partially retractable. When a larva is done feeding on a snail (or slug or earthworm) it will de-slime all of these parts with the hooked, fingerlike projections of the holdfast organ (pygopod) located on the last abdominal segment. The head is also fully retractible (see previous post). These larvae are extremely active, so really hard to photograph.

Colin Purrington Photography: Insects &emdash; Pyractomena borealis mouthparts

Colin Purrington Photography: Insects &emdash; Pyractomena borealis mouthparts

Colin Purrington Photography: Insects &emdash; Pyractomena borealis mouthparts

Colin Purrington Photography: Insects &emdash; Pyractomena borealis mouthparts

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Pyractomena borealis

Pyractomena borealis (Lampyridae) exploring the surface of trees on a warm winter day in February. The third photograph shows how they can retract their head under the carapace like a turtle. At first I thought they might be foraging — they are highly predaceous, and hunt slugs and earthworms (in packs!) by first injecting them with paralytics. But they might have just been looking for a place to pupate, because it’s time for that. Adults will emerge sometime in early Spring to be the first fireflies in the area. The larvae are bioluminescent, too. The hypothesis about why the larvae glow is that it evolved first as an aposematic trait in larvae, warning mice and toads of the presence of lucibufagins, steroidal toxins in the hemolymph. It’s thought that the adult habit of using flashes is secondarily evolved, millions of years after the larvae evolved the ability to glow. The ability of larvae to glow even predates the origin of the Lampyridae, I gather. For more enlightening details, see Branham and Wezel (2003)Stanger-Hall et al. (2007), and Martin et al. 2017.

Colin Purrington Photography: Insects &emdash; Pyractomena larva

Colin Purrington Photography: Insects &emdash; Pyractomena larva

Colin Purrington Photography: Insects &emdash; Pyractomena larva

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