The Parasite Files
loom | June 28, 2008I'm sure you'd like to pretend that you have nothing in common with a tapeworm.
A tapeworm starts off as an egg which then develops into a cyst. Inside the cyst is a ball-shaped creature with hooks that it can use to crawl around its host before growing into an adult. Many species are made up of dozens or hundreds of segments called proglottids. Each proglottid may be equipped with both eggs and sperm-making organs. As an adult, a tapeworm also grows a head-like end often equipped with suckers or hooks of its own. This strange organ is called the scolex. (The shark tapeworm in this photo is…
loom | June 27, 2008It feels like a homecoming: I'm among hundreds of people who live for parasites.
I arrived in Arlington Texas this afternoon to attend the annual meeting of the American Society of Parasitologists. I'm going to give a talk tomorrow about the public awareness of parasitology, talking about my long-term relationship with the beasties in books, articles, blogs, and beyond. But till then, I get to hang out with parasitologists. I've met a lot of the people here over the years, like the leech-master Mark Siddall, and I've read the work of a lot of people I'm just meeting (work on things like how…
loom | June 10, 2008In a couple weeks I head to Texas to the annual meeting of the American Society of Parasitologists to talk about parasites in pop culture. The symposium is called, "Parasitology: Public awareness through literature, art, and film." Our panel has lots of creepy movie clips in store, plus other sorts of media including books and this humble blog. But maybe we'll need to tack on "music" to the end of that list in the symposium title. Inspired by a post of mine on the gorey glam of Ampulex compressa , the emerald cockroach wasp, a band called Super Duper has composed a song. The video is below,…
loom | June 3, 2008A caterpillar's life is not an easy one. The plants that it eats make toxins to make it sick. Birds swoop in to pluck it away and feed it to their chicks. But the most horrific threat comes from wasps that use caterpillars as hosts for their young. These parasitoid wasps are among my favorite creatures (see my post on the emerald cockroach wasp, which attacks cockroaches like a neurosurgeon). So it was with eye-popping delight that I read a new paper in PLOS Biology One about how another species of wasp in Brazil attacks another caterpillar. Glyptapanteles glyptapanteles is more than just…
loom | February 23, 2008It's fun to write about discoveries, but mysteries are important too. In my latest column for Wired.com, I explore the mysterious death of honeybees, and the trouble scientists are having pinning down a culprit.
Honey Bees Give Clues on Virus Spread
loom | December 1, 2007Last year I wrote about the emerald cockroach wasp, Ampulex compressa, which injects venom into cockroaches to turn them into zombie hosts for their parasitic offspring. (More posts on Ampulex here.) The scientists I wrote about have been trying to figure out what exactly the venom does to the nervous system of their victims, and they've discovered that it interferes with a neurotransmitter called octopamine. New Scientist has an update. And they also have a link to a YouTube video that offers more than you may want to see of this awesome parasitic manipulation.
loom | September 27, 2007It is a day to write about Giardia, and I am happy to say that I cannot do so from firsthand experience. Friends of mine have suffered infections of Giardia in their gut, but they haven't been terribly forthcoming about the details. It's not fun, they assure me, and it can last for months. Unpleasant as it may be up close, though, Giardia is one of the most fascinating, most enigmatic creatures on the planet (from a safe distance). Scientists do not yet quite know what to make of this single-celled parasite, but one possibility is that Giardia holds secrets to some of the key steps in the…
loom | September 8, 2007Science Made Cool writes from Tokyo, describing the world's only parasite museum. Someday I'll get there...
Sadly, the keychain with the sushi worm embedded inside is not for sale online...
Update: Mark asks whether there's an American museum in Maryland. It's a collection, not a museum. I write about my visit there in Parasite Rex. A wonderfully creepy place, but no parasite-entombing keychains for sale.
loom | August 13, 2007Parasitoid wasps (or rather, one group of them called the Ichneumonidae) are the subject of one of Charles Darwin's most famous quotations: "I cannot persuade myself that a beneficent and omnipotent God would have designedly created the Ichneumonidae with the express intention of their feeding within the living bodies of caterpillars."
Scientists have learned a lot more about parasitoid wasps since Darwin wrote about them in 1860, and their elegant viciousness is now even more staggering to behold. Not only do they devour their hosts alive from the inside out, but they also manipulate the…
loom | April 3, 2007Reports are coming out this morning on a new study on one of the Loom's favorite organisms: Toxoplasma gondii, the single-celled parasite that lives in roughly half of all people on Earth and has the ability to alter the behavior of its host. I reported on the research last June in the New York Times, when the Stanford researchers reported their results at a scientific conference. It's nice to finally get the results on paper, though.
The study is a fine example of an underappreciated part of science: replication. In 2000 British researchers carried out a study in which they put healthy and…
loom | March 7, 2007 If pubic lice are not the sort of thing you want to be seen reading about, let me give you the opportunity to close your browser window right now. But if you're at all curious about the secret that pubic lice have been keeping for over three million years, the tale of a mysterious liaison between our ancestors and the ancestors of gorillas--read on.
Many parasites tend to stick close to their hosts. A parasitic wasp may wander through forests and fields to find a caterpillar from a single species of butterfly in which it will lay its eggs. Blood flukes taste the water of their ponds for…
loom | February 19, 2007Darwin gave a lot of thought to the strangest creatures on this planet, wondering how they had evolved from less strange ancestors. Whales today might be fish-like warm-blooded beasts with blowholes and flukes, but long ago, Darwin argued, their ancestors were ordinary mammals that walked on land with legs. His suggestion was greeted with shock and disbelief; neverthless, scientists have found bones from ancient walking whales. Humans, Darwin argued, evolved from apes, most likely in Africa where chimpanzees and gorillas are found today. And today scientists have found about twenty different…
loom | December 4, 2006Thanks to PZ Myers for calling attention to this superb video of Corydceps, a parasitic fungus that drives its insect host up a plant before growing a spike out of its head. Leave it to David Attenborough, master of the nature documentary, to bring the beauty of this parasite to video. I've seen photographs of Cordyceps before, but I never knew it made such a graceful entrance.
What's particularly cool about Cordyceps is that it is not alone. Other parasites drive their hosts to bizarre heights. Another fungus, called Entomophthora muscae, drives houseflies and other insects upwards, climbing…
loom | November 14, 2006Well, the talk at Cornell last week went very well. Thanks to everyone who came. If you want to hear me wax rhapsodic about parasite manipulations (and explain how scientists study their evolution), you're in luck. Cornell has put the video of the talk online. The image is pretty small on the screen, so I decided to post the slide show on my web site here. I suggest opening two screens and advancing the slides as the talk progresses.
At first the sound is a little scratchy on the video and the light balance takes a while to get properly adjusted. But don't give up--it evens out. You may also…
loom | November 7, 2006Attention all Loom readers in the Cornell University area: I'm heading up to Ithaca to give a talk tomorrow on a subject near and dear to my heart--how parasites turn their hosts into puppets and slaves. I'll be at the David Call auditorium in Kennedy Hall at 4 pm. The lecture is open to the public and will, of course, include a very creepy Powerpoint. Details here, map here.
loom | October 12, 2006Toxoplasma, that mind-altering, cell-manipulating, all-around awesome parasite that sits in the brains of billions of us, is back in the news. Infection with the parasite raises the chances a woman will have a boy from 51% to 72%. The average ratio of boys to girls at birth is 51%. Women with high levels of antibodies to Toxoplasma, scientists found, have a 72% chance of having a boy. While many effects of Toxoplasma probably have something to do with adaptations that allow the parasite to thrive and spread successfully, this one seems more like a side-effect, albeit a dramatic one.
Source:…
loom | August 4, 2006 I'm heading out of blog contact for a couple days, so allow me to share one of my favorite posts, from last January--on wasps that perform brain surgery.
I collect tales of parasites the way some people collect Star Trek plates. And having filled an entire book with them, I thought I had pretty much collected the whole set. But until now I had somehow missed the gruesome glory that is a wasp named Ampulex compressa.
As an adult, Ampulex compressa seems like your normal wasp, buzzing about and mating. But things get weird when it's time for a female to lay an egg. She finds a cockroach to…
loom | August 1, 2006Once again, I hear the siren song of Toxoplasma, the parasite that dwells in the brains of 50 million Americans.
Toxoplasma gondii is an extraordinary creature, whose exploits I've chronicled in previous posts , an article in the New York Times and my book Parasite Rex. This single-celled organism has a life cycle that takes it from cats to other mammals and birds and back to cats again. Studies have shown that the parasite can alter the behavior of rats, robbing them of their normal fear of cats--and presumably making it easier for the parasites to get into their next host.
Toxoplasma is…
loom | June 19, 2006Next time I go to the doctor, I think I'll get him to give me a test for Toxoplasma. Fifty million Americans have the parasite, so I wouldn't be the first. And if I was carrying it around in my head, that might explain why it's so fascinating to me.
I first encountered the strange ways of this single-celled creature while working on my book Parasite Rex, and since then I've tried to keep up with new research on what makes it so successful. In January I wrote on the Loom about a potential link between Toxoplasma and schizophrenia.
In Tuesday's New York Times I have an article that surveys…
loom | May 15, 2006If you keep a vegetable garden, there's a fair chance you'll encounter a grisly sight this summer. Some poor caterpillar will be clutching a leaf, with the pupae of parasitic wasps sprouting off its back. It has just died in a most grotesque way. A wasp has zeroed in on the caterpillar and injected eggs into its body. The eggs hatched, and the larvae devoured their hosts from within, keeping it alive until they were ready to emerge.
What makes this sight all the more grotesque is the fact that the plant the caterpillar is sitting on may have been an accomplice to the crime. When caterpillars…