Wasp Larvae can take over spider's brain

CosminaPrisma

I found this to be an incredibly fascinating but incredibly gross phenomena. I'm wondering if any of you know any more about the science behind how the wasps actually induce the spiders behavior change....

The article is here....
http://www.damninteresting.com/?p=17

CosminaPrisma

PDF of the paper found here
http://www.americanarachnology.org/J..._29_03_354.pdf

zoobyshoe

I think the guy in the article has the most plausible explanation, that it's chemical. The larva get the web they need by kind of poisoning the spider, causing it to delete all but two of it's usual steps in webmaking.

I suppose if you were born in a spider web and ate spider for your first meals, you'd return to those scents or pheromones as an adult ready to lay eggs.

Still, you have to wonder at the weirdness of how this started in the first place.

Q_Goest

Hi CP, very cool article. I saw a TV show about this some time ago, though I can't add anything unfortunately. I wonder if these parasites release a virus as opposed to just a chemical though. A virus might go directly to rework the DNA of the host, though I suspect it would take some time for it to take affect.

I also looked up a variety of links on that page, the one about the fish tounge and crab zombies are pretty fascinating. But the one that bothered me the most was one about Toxoplasma gondii. Actually, I think it was a link to a link. Apparantly 50% of people in the world are infected with this parasite! Seems like something worth doing a JC article on if I can find a good one.

iansmith

the interresting thing is that several parasitic wasp have viruses integrated in their genome and that are expressed only in the reproductive tracts of females wasp. these viruses are injected with the eggs when they are laided. As far as I know, the viruses do not interact with the brain but they are there to stop the immune response of the host insect against the wasps eggs.

http://www.ncbi.nlm.nih.gov/entrez/q...=pubmed_docsum
http://www.ncbi.nlm.nih.gov/entrez/q...=pubmed_docsum

zoobyshoe

I had no idea there was such a thing as a parasitic wasp. I thought they all raised their larva in paper combs. It also amazes me anyone knows so much about their genes.

Q_Goest

Thanks for the info, iansmith. So the virus is there to prevent an immune system responce. Would it seem likely then, that viruses are also used to force the spider to create the different web? It would seem to me the information for how to build the normal web must be encoded in the spider's DNA, do you think that's true? If so, it might be that by testing the normal DNA from a healthy spider and the potentially reworked DNA from a dead one might indicate this.

Hurkyl

You did notice that it said the spider recovers after a while, if we remove the larvae just before they actually kill it, right?

Q_Goest

Yes, good point Hurkyl. But then again, I have the flu right now and expect to recover from that.

iansmith

Yeah they are called parasitoid and you also have wasp that infect eggs of other parasitoid. The parasitoids are very important because they are used as a form of biological control of pest insects (i.e. an alternative to chemical pesticide) and that is why people have in interrested.

zoobyshoe

Ah, that clicks it all into place then. Pretty interesting.

zoobyshoe

You will if you can avoid spinning a funky web.

Monique

If I'm correct, people infected with this parasite in the brain are more likely to be involved in accidents, since they take more risks in life. Apparently the parasite diminishes their power of judgement.

Mk

In the U.S. NHANES III national probability sample, 22.5% of 17,658 persons >12 years of age had Toxoplasma-specific IgG antibodies, indicating that they had been infected with the organism. It is thought that between 30% and 60% of the world's population are infected. However, there is large variation countries: in France, for example, about 85% of the population are carriers, probably due to a high consumption of raw and lightly cooked meat.

I found it interesting that 85% of French have it because of the meat they eat.