My Uncle was telling me some story about a wasp laying it’s eggs in one certain type of beetle, the larva would eat the beetle from the inside out leaving the heart and lungs for last. The idea being that the wasp larva wanted to keep its host alive and well for as long as possible. He has a degree from MIT, but the story was couched in a story that kind of defended Intelligent Design, so I’m really not sure what to make of it. I’m assuming that it’s true. Has anyone else heard of this? What species were involved?
… Both those links go to the same place.
Not sure how this parasitic situation could be construed as defending “intelligent” design. Quite the opposite. Any god who came up with this as a means of reproduction for one of its creatures is not the kind of deity I’d like to have anything to do with.
On the contrary, I’ve heard of this wasp as well, and its Alien-type method of reproduction quite clearly demonstrates to me the random cruelty of this world we live in, created by uncaring evolution and driven by the chance of natural selection.
It’s perfectly true, and remarkably common.
The exact species could be almost anyhitng. The most common parasitoid group to do this are the wasps, particularly the Ichneumons and Ichnuemenoids, but there are countless other largely unrelated wasp species such as the tarantula hawks that use the same strategy. The use of live prey as pupal incubators seems to have evolved multiple times within the hymenoptera.
Do a Google search to get all the information you could possibly want.
The use of the concept to defend Intelligent Design is suprising since everyone from Charles Darwin and Mark Twain through David Attenborough to Stephen Jay Gould have used this as their perfect counter-example to intelligent deisgn. Essentially there argument is “What sort of sadist would create a system where an animal is eaten alive, paralysed but fully conscious.”
Leaving the head capsule alone and eating all of the rest, seems to contradict my Uncle’s story (not that it was correct). He described a larva eating around specific organs (lungs and heart), suggesting that the larva knew which parts to leave alone. I’m guessing that the larva would not be able to enter the head cavity internally, but that’s just a WAG.
Basically, if the larva eats everything in the particular section of the grub that it’s in, the story does not hold water. If it eats around specific organs on purpose, the story has validity. I’m starting to think that the story was a bit bunkish.
He’s the one making the claim; get him to tell you the species or admit it doesn’t exist.
Heh. He claimed to be citing Darwin saying something along the lines of “Does this sound like something that could result from series of trial and error mutations?”
Then he said that his other brother would have called him a “Reaganite Luddite” for having even suggested such a thing.
If sadism is any factor in this, which I don’t think it is, what about other insects that paralyze and eat their prey? Or prey that simply get eaten alive until they just die?
Stupid question perhaps, but do beetles have hearts and lungs as we know them?
According to this staff report, insects don’t have lungs so that’d make the “eating around them” part a bit tricky.
Insects don’t have lungs, but I’m not sure why the parasitic larvae leaving “essential” organs for last proves ID. Maybe those bits taste bad. And maybe they taste bad because the larvae that thought they tasted bad had fresher food for longer, and thereby survived better than larvae who killed their hosts quickly.
The way that the conversation in question got started makes his reply all the more suspect. We were out watching the Perseids meteor shower and he (Uncle) said “Do any of you know how old the Earth is?” I said 10,000 years and chuckled. He knew I was making a dig at ID theories. I have no idea exactly how long ago people that subscribe to that thinking think the Earth was, but he got the point. The answer to his question, according to him, was 13 billion years. My Dad said “You mean the Big Bang was 13 billion years ago?” He said “Whatever started it, started around 13 BYA”. Then he tells us the story that the OP describes. I’m glad he decided to drop the matter.
Sounds like he takes the hedge-your-bet attitude that my dad subscribes to. God as a general mover who started things going, evolution as his tool.
At least he’s not all the way crazy
i cant offer a good link or a cite to back this up, but i very clearly remember reading about that kind of wasp, whose larvae did indeed save the critical organs until the end. i know i read it somewhere, and i would bet it was in either a book by richard dawkins or in this other book on parasites, whose exact name and author i’ve since forgotten.
this webpage here:
says that “Parasitoid larvae hatch and grow by feeding on the bodily fluids or the internal organs of the host (usually the non-vital parts first). The host dies when the fluid has been sucked dry or its internal organs cease to function.”
wants you to pay $19 for an article about braconid parasitoids, but the blurb on google says “t has been shown that a related braconid parasitoid refrains from eating the host’s nervous system and kills the host only after the latter has found a …”
and i cant trick google into letting me read the end of the sentece.
so basically all i have to offer is a half-sentence tease from google and my assurance that those wasps do indeed exist, whose larvae eat around the vital parts of their host so that the host goes on living for as long as possible, which i know because i read about it in some book i cant remember.
so take of that what you will. sorry i could be helpful in a more scientifically exacting manner.
The argument is that there is a major difference between designing an animal that eats another animal, even of the death is less than painless, and one designing that paralyses an animal and eats it alive over the course of 6 months. It is the same as the difference between a man that deisgns a weapon to kill someone, and designing weapon that kills someone over the coarse of 6 months while they remain fully conscious. Sometimes killing is necessary, as humans we accept that. We find it harder to accept that it is necessary to kill slowly and painfully.
We wouldn’t condemn a human that killed an animal, even if they unintentionally failed to kill it instantly. If the same human designed a system specifically and deliberately to cut an animal to pieces so he could eat over 6 months while it remained alive and conscious he becomes a monster.
Lungs, no. the do have hearts of a sort. And yes, the wasp larvae in many groups carefully avoid eating the heart, just as the avoid eating the brain and the skin until just before they pupate.
Why more ID supporters don’t take this view is beyond my comprehension. Admittedly, I’m kind of in that camp too, but more out of “hedge my bet” than any sound reasoning. I mean, how does one disprove an entity that by definition can change any and all rules? OK, enough of that from me. If this thread winds up in GD, I’m not gonna follow up on it. I’d really like for it to stay based in fact if at all possible.
BTW, thanks for all the info guys. I’m curious to see if anyone can cite the claims made by yams!!, it sounds much closer to what the story depicted.
Is the insect in question feeling pain? Wouldn’t the shutdown of the central nervous system keep them from being in agony? I doubt that we can prove if they feel pain or not during this process.
I’ll not get into the role that sadism might or might not play in arguing about ID, mostly because I don’t want this thread to end up in GD. A scientific answer is really what I’m looking for here.
Since a short post might tend to get the most reads, please don’t force this thread into GD. Thanks.
It’ questionable if insects can feel pain at all. There woould certainly be no evolutionary benefit in them feeling pain, But that is a separate issue when discussingthe concept of ID.
The CNS isn’t shut down, that’s the whole point. The CNS remain perfectly functional to allow the animal to remain alive. The motor nerves or at best some of the motor centres of the brain are shut down. The insect remains fully sensate as far as anyone can tell. In the most extreme cases the venom does so little damaged that the wasp leads it around by aternately biting on one or the other antennae. In other cases the wasps parasitise teh larvae of othe rinsects which continue to feed whiel being eaten alive. The CNS is so intact that the insect can still walk and respond to stimuli when the larvae start eating it. It just can’t run away.
As I said, what was depicted is well known to science, well documented and has been for centuries. It is in no way controversial.
I think Richard Dawkins also touched on this topic with The Extended Phenotype.
No thread about insect parasitic larva is ever going to be complete without mention of the Emerald cockroach wasp (my apologies if it has already been mentioned).