How Pubic Lice suck (your blood)

crab louse

A pubic louse, or crab louse

I became an unwilling expert on pubic lice a couple years ago when I bought “crabs” online at the request of a reporter. Really. It’s a long story, and you can listen to a version of it here; the abridged version is someone calling himself “Lice Lice Baby” claimed he would sell you “Giant Japanese Pubic Lice” as pets.  He re-branded his crab lice as “Seamonkeys in your Pants.”

The French call pubic lice “papillon d’amour”, but for all the happy euphemistic talk about “the ultimate sharing of your love,” crab lice are blood-sucking parasites. At the time, my primary concern was pointing out that deliberately infesting yourself with pubic lice was probably not a very good idea, and a public health risk.

This somehow made me the go-to person online for pubic lice, which is not, frankly, an expertise I particularly aspired to.  I was talking to someone recently about public lice (now a regular occurrence) and I realized that I didn’t know the specific mechanism by which pubic lice suck (aside from the fairly obvious suckage of being infested). I did a little research, and what I found out actually made pubic lice creepier. I did not think that was possible.

One of my primary resources was a paper with this wonderful title:

BURNS D.A. & SIMS T.A. (1988). A closer look at Pthirus pubis, British Journal of Dermatology, 118 (4) 497-503. DOI:

A closer look, indeed! This is a scanning electron micrograph of the sucking end of a crab louse, magnified about 1000 times.

pube lice haustellum

Pthirus pubis is a member of the Order Anoplura or ‘sucking lice’. It is a solenophage (vessel feeder—from the Greek ‘pipe’ + ‘eating’), introducing its mouthparts directly into a blood vessel to withdraw blood. The components of the mouthparts responsible for probing the skin and piercing a blood vessel are kept withdrawn within the head unless the insect is feeding… In the front of the head is a small, snout-like tube, the haustellum, which is soft, eversible, and armed with teeth. Figure 5 shows the haustellum retracted, and the buccal teeth are clearly visible.

But wait! There’s more!

When the louse is about to feed… the buccal teeth rotate outwards. The teeth cut into the epidermis [skin] with a movement compared to that of a rotary saw, and the haustellum is gradually driven into the dermis. It eventually comes to rest with the buccal teeth fully everted, anchoring the mouthparts in the skin….The stylets are advanced into the dermis as a single bundle and probe for a small blood vessel. Once the stylet bundle has pierced a blood vessel feeding begins.  [emphasis mine]

electron micrograph of crab liceEgad.  That little tube? It’s like a hypodermic needle going into one of your blood vessels.

If you haven’t already unconsciously crossed your legs while reading this, this next bit should do the trick. One of the characteristic signs of pubic lice feeding is little blue spots on the skin. It’s a combination of blood leaking out after that mouth-needle is withdrawn and a reaction to the saliva of the louse.  Another symptom of a crab louse infestation is described as “black powder in your underwear.”  That powder is your dried up blood, after the louse has digested it and pooped it out.

I’m not sure that anyone besides me really needed to know this information, but it is a fascinating example of how insect mouth parts have evolved to make them highly successful external parasites!

Related Posts:

The GOP War on Caterpillars

Politics delivered a bizzare insect soundbite this week. A GOP leader was being questioned about policies mandating medically unnecessary transvaginal ultrasounds, limiting access to birth control, and other recent policy initiatives considered anti-woman.  His response? 

Priebus rejected the idea that Republicans are waging a war on women.

“If the Democrats said we had a war on caterpillars and every mainstream media outlet talked about the fact that Republicans have a war on caterpillars, then we’d have problems with caterpillars,” Republican National Committee Chairman Reince Priebus said in an interview on Bloomberg Television’s “Political Capital with Al Hunt” airing this weekend. “It’s a fiction.

caterpillar How the HELL do you explain that thought path??
Women –> Sluts –> Uterus control –> CATERPILLARS.

Also? Denying there is a war on women only works if, in fact, there isn’t a war on women.  Hundreds of bills are being introduced all over the US that limit women’s rights.  Just last week Wisconsin quietly revoked an equal pay bill.

The analogy with insects doesn’t work either if, in fact, there actually is a GOP war on caterpillars.  Let’s continue to use Wisconsin as an example. Wisconsin sponsors a major project to kill the Gypsy Moth. Go look. It’s WAR, people. There are areas clearly marked for “suppression.”

Texas recently cut health services to many women. They also are persecuting cactus moth caterpillars. In fact, there is a tri-state consortium devoted to killing these caterpillars; here’s some representative language:   “In the wake of the Cactoblastis, only death and destruction are found, presenting a threat to human welfare…”   Sounds pretty warlike to me!

Michigan, a state that recently banned same-sex partner benefits, has quarantines in many areas, and routinely stops people with firewood for warrantless searches. What are they looking for? GRUBS. The Emerald Ash Borer is marked for elimination.  You are even encouraged to turn in suspicious characters by calling a hotline.

change

The GOP-controlled House introduced a “Reducing Regulatory Burdens Act” in 2011 that would reduce pesticide regulation, including removing some pieces of the Clean Water Act that currently restrict pesticides in watersheds.

There is evidence of flip-flopping by Mitt Romney on the caterpillar issue. He labeled a project to control the invasive species of winter moths as “porkbarrel spending” in 2006, and didn’t fund it.  His current position on funding the War on Caterpillars is unclear.

Clearly, the War on Caterpillars is REAL.  Of course, there is a reason why caterpillars are targeted by both the GOP and farmers.* It’s simple math that goes all the way back to Malthus.  Populations have the potential to grow faster than their food supply. So, if you want to control an insect pest, you attack its reproductive cycle.

But why in the world would you want to prevent women from having access to birth control, or the ability to control their own bodies? This seems counter-productive for a bunch of fiscal conservatives.  How will we provide water and food for a expanding population? How will those babies be employed in the future when they grow up? How will all those kids be educated? We are building more prisons than schools, which doesn’t bode well for anyone’s future prospects.

Obviously, I think women should have control over their bodies because it’s a basic human right (recognized since 1968 by the UN, in fact).  It just seems like the current focus on womb control is very short-sighted from a fiscal/living-in-the-real-world point of view, as well.

Legislation was introduced to require women to provide a written explanation about why they wanted birth control to their employers. Legislation has been introduced to define you as pregnant 2 weeks before conception. Women who have miscarriages are charged with murder.   This is some serious heinous fuckery, people.  It’s 2012. The state should not be getting all up in my lady business.

There is an upside to all this. The best thing to come out of the GOP war on caterpillars was the explosion of #GOPWarOnCaterpillars on Twitter.  This charge was led by the wonderful John Scalzi, who decided see if he could get the tag to become a “trending topic”.  Here are some of my favorites–feel free to suggest more slogans in the comments!

Share
CATERPILLARS AREN’T REAL CATS. OR PILLARS. WHY TRUST THEIR LIES #GOPWarOnCaterpillars
Thu, Apr 05 2012 16:53:14
  1. Share
    IF WE LEGALIZE CATERPILLAR MARRIAGE, THE CHILDREN WILL BE CONFUSED. MOSTLY BY CATERPILLARS GETTING MARRIED. #GOPWarOnCaterpillars
    Thu, Apr 05 2012 16:51:09
  2. Share
    RT @markokloos: THE CONSTITUTION DOESN’T MENTION THE RIGHT TO PUPATE #GOPWarOnCaterpillars
    Sat, Apr 07 2012 18:43:14
  3. Share
    BUTTERFLIES AND RAINBOWS: NOT A COINCIDENTAL PAIRING #GOPWarOnCaterpillars jezebel.com/5899482/war-on…
    Fri, Apr 06 2012 04:16:37
  4. Share
    ECDYSIS IS JUST A FANCY WORD FOR STRIPPING! CATERPILLARS=SLUTS! #GOPWarOnCaterpillars
    Thu, Apr 05 2012 17:03:05
  5. Share
    Back in my day, we told the caterpillars to just hold an aspirin between each pair of knees. Took a whole bottle, tho. #GOPWarOnCaterpillars
    Thu, Apr 05 2012 18:19:10
  6. Share
    YOU SHALL HAVE MY CHRYSALIS WHEN YOU PRY MY COLD DEAD FINGERS FROM IT. #GOPWarOnCaterpillars
    Thu, Apr 05 2012 16:37:24
  7. Share
    .@scalzi HOW CAN YOU TRUST A CATERPILLAR WHEN THEY ARE THE WORLD’S OLDEST SPIN DOCTORS? #GOPWarOnCaterpillars
    Thu, Apr 05 2012 17:01:51
  8. Share
    CATERPILLARS WILL FORCE YOUR CHILDREN TO READ ABOUT THEIR LIFE CYCLE IN SCHOOL #GOPWarOnCaterpillars
    Thu, Apr 05 2012 16:56:55
  9. Share
    @scalzi In the tradition of “Freedom Fries,” Caterpillar Trucks will henceforth be called Bald Eagle Trucks. #GOPWarOnCaterpillars
    Fri, Apr 06 2012 01:22:17
  10. Share
    I don’t believe there is a #GOPWarOnCaterpillars. After all, Republicans support the right to woolybear arms.
    Thu, Apr 05 2012 18:04:52
  11. Share
    Breaking: Republicans oppose law to require paid leave time for metamorphosis, calling it “socialist”. #GOPWarOnCaterpillars
    Fri, Apr 06 2012 13:04:44
  12. Share
    LOOK ALL I’M SAYING IS METAMORPHOSIS IS A LIFESTYLE CHOICE #GOPWarOnCaterpillars
    Thu, Apr 05 2012 18:57:54
  13. Share
    If butterflies came from caterpillars HOW COME THERE ARE STILL CATERPILLARS?! #GOPWarOnCaterpillars
    Thu, Apr 05 2012 21:47:03
  14. Share

    #GOPWarOnCaterpillars http://twitpic.com/9634g4
    Thu, Apr 05 2012 19:46:01

*Actually, these are all invasive species and it’s ok with me if they kill them. But that kind of detracts from my point, so it’s a parenthetical down here.