
Emerald cockroach wasp - Reproductive behavior and life cycle - alexandros
http://en.wikipedia.org/wiki/Emerald_cockroach_wasp#Reproductive_behavior_and_life_cycle
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Arun2009
> Over a period of eight days, the wasp larva consumes the roach's internal
> organs in an order which guarantees that the roach will stay alive, at least
> until the larva enters the pupal stage and forms a cocoon inside the roach's
> body.

Instances of 'inborn intelligence' never cease to amaze me. How in the world
do the larvae _know_ in which order to eat the organs?!

If you have an instinct that is pretty low-level (say, pulling your hands away
from a hot object), you could argue that your biology has been selected by
evolution to respond in a particular way to that stimulus. I can also
understand adults exhibiting a higher-level of intelligence - they could have
learned it from their community or from direct experience. But tabula rasa
minds exhibiting complex intelligence is just mind boggling.

~~~
phaedrus
Suppose you have two variations of a gene; one produces larvae that prefer the
taste of a vital organ, and eat that one first. The other variation prefers
the taste of a less important organ, eating that first and eating the
important organ only when it has exhausted its preferred option. If the second
one is on average 5% more likely to complete its growing before the roach dies
and its food supply rots, the second variation is likely to displace the
first.

Why would larvae eat only one organ at a time in the order of taste preference
in the first place? Well if two variations of a gene exist, and one produces
larvae that are not picky and damage many organs while feeding, while another
produces larvae that are picky and thereby confine their damage to.one organ
at a time, then if the second behavior is more successful it will begin to
replace the first.

The central.message of modern Darwinism is the accumulation of small changes
can lead to big evolutions. Obviously I cannot say what the exact mechanism of
this instance was but what I gave are examples of the types of incremental
changes that may have contributed. Your incredulity is based on a straw man
argument: you ask how does the animal know what the right order is, as if that
had to come all at once ex nihilo.

~~~
borism
Let's first start by verifying that there actually exists such behaviour -
there are no citations for larvae lifecycle part in Wikipedia and I couldn't
find any reference in papers.

Maybe larvae just consumes a little of every organ it can get to. The whole
story about it consuming non-essential organs first seems quite fishy - how
many of those do cockroaches have anyway? Even if that's true, after eating
away few organs you pretty sure to get organism failure no matter what order.
Doesn't seem very smart strategy to me.

~~~
51Cards
This would be the article you're looking for...

[http://onlinelibrary.wiley.com/doi/10.1111/j.1748-1090.1993....](http://onlinelibrary.wiley.com/doi/10.1111/j.1748-1090.1993.tb03531.x/abstract)

You'll need a Wiley Online Library membership to read all of it.

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rev087
Wow. When I was a kid I was fascinated by watching bugs for hours, I even kept
(and fed by capturing mosquitoes) garden spiders with their eggs in a plastic
box, just to watch the spiders catch the prey and the egg hatch those dozens
of litltle spideys.

But the one mysterious bug that I knew nothing about was this one. My parents
couldn't tell me what was it, nor it appeared in any of my books and
magazines...but I was completelly fascinated to see it carrying roaches around
at my grandma's front yard. At the time I thought the green fella was
hypnotizing the roach then "riding" it to it's place for dinner.

You can't imagine how happy I am to finally learn the name of that bug and
what in the world he did with the roaches, thank you!

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tnai
Creepy video here <http://www.youtube.com/watch?v=Hxe60BcHbUA>

Parasitoids have fascinating life histories. I'd thoroughly recommend the book
"Parasitoids: Behavioral and Evolutionary Ecology" by Charles Godfray.

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Kliment
With photo at:
[http://scienceblogs.com/loom/2006/02/02/the_wisdom_of_parasi...](http://scienceblogs.com/loom/2006/02/02/the_wisdom_of_parasites.php)

~~~
thorsview
The comment thread on this article is over 200 posts. Mostly a heated
creationist vs evolunist debate, but there is some interesting reading in
there. It is hard not to ponder how such a complex set of behaviors came to be
through natural selection alone. However, one comment that I found
particularly on point is posted below:

"I have a suggestion for how this evolved. The initial sting to the cockroach
would obviously make the cockroach's escape part of its brain light up like
crazy. If the wasp then goes to find the most active part of the cockroaches
brain, i'd imagine this would be the escape area. I believe there are simple
rules which build up to create complex systems. These simple rules, like the
active neuron sensor, help to create shortcuts to how a creature evolves. If
you look at the recent darpa challenge, involving the teaching of a car how to
drive across unfamiliar terrain, it managed to convince the team it was
working by using just the rule of keeping the grass equally distant on the
right and the left. It hit a bridge and swerved so the guy onboard had to grab
the wheel! But the point is simple rules can lead to complex seeming actions."
Posted by: Rob Levy | February 4, 2006 4:28 PM

~~~
rezaprima
The hard part is proving that this, or any other evolutionary scenario, is
what actually happened.

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po
_Researchers believe that the wasp chews off the antenna to replenish fluids
or possibly to regulate the amount of venom because too much could kill and
too little would let the victim recover before the larva has grown._

I don't understand either of those explanations. Do roach antenna have fluids
in them? How does chopping off antenna regulate venom which is already in the
roach's brain? Does anyone get this part?

~~~
po
OK this video (which is quite good) seems to answer it:

[http://www.youtube.com/watch?v=m-p_4mp-
RtA&p=E330837E95B...](http://www.youtube.com/watch?v=m-p_4mp-
RtA&p=E330837E95B3725D)

The clipped antenna leaks roach blood. Now I'm off to bed for some sweet
nightmares.

~~~
mokchuk_
Wasps are amazing creatures. well over 100,000 species of them are parasites.
Here's another complex insect parasite video involving caterpillars that
stowaway in ants nests and the wasps that lay eggs in them, from
Attenborough's Life in the Undergrowth BBC series:
<http://www.youtube.com/watch?v=GCo2uCLXvhk>

Also other species hijack acorns growth to lay offspring within, and are then
in turn preyed upon by other wasps:
[http://www.youtube.com/watch?v=CzXccvoJThI&NR=1](http://www.youtube.com/watch?v=CzXccvoJThI&NR=1)

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jared314
This is what evolves when you can't keep food fresh. Thank you Jacob Perkins.
(<http://en.wikipedia.org/wiki/Refrigerator#History>)

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bendauphinee
I have to say, the world around us has some scary creatures in it. This, of
course, being one high on that list. Definitely fodder for some terrifying
nightmares.

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najirama
Can someone with state-of-the-art knowledge of biology explain how in the
world something like this could have evolved?

It was my rudimentary understanding that Lamarckian inheritance had been
debunked; how else then could such precise knowledge of a cockroach's
neurological functions have been passed on to the subsequent generation from
the primary generation whence such a technique was first employed?

~~~
hugh3
I don't have state-of-the-art knowledge of biology, but you'll note from the
article

 _While a number of venomous animals paralyze prey as live food for their
young, Ampulex compressa is different in that it initially leaves the roach
mobile and modifies its behavior in a unique way._

This suggests to me that the ancestors of this wasp would simply paralyze the
roach and lay eggs inside, and this behaviour evolved from that.

~~~
borism
_This suggests to me that the ancestors of this wasp would simply paralyze the
roach and lay eggs inside, and this behaviour evolved from that._

That would be backwards evolution.

From the scienceblog link:

 _Amuplex is not technically a parasite, but something known as an
exoparasitoid. In other words, a free-living adult lays an egg outside a host,
and then the larva crawls into the host. One could easily imagine the
ancestors of Ampulex as wasps that laid their eggs near dead insects--as some
species do today. These corpse-feeding ancestors then evolved into wasps that
attacked living hosts. Likewise, it's not hard to envision an Ampulex-like
wasp evolving into full-blown parasitoids that inject their eggs directly into
their hosts, as many species do today._

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Luyt
This reminds me of phorid flies, the natural enemy of the fire ant. The larva
of a phorid fly eats its way into the head of the ant, decapitates the ant by
dissolving its neck with enzymes, then cocoons in the head.
<http://en.wikipedia.org/wiki/Fire_ant#Natural_predators>

Nature is beatiful ;-)

~~~
sliverstorm
The ant's first mistake was attaching it's head with a membrane...

Obviously ants are one of the most successful creatures in the world, but a
membrane!? Wow.

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paufernandez
Okay, now that you know... just start counting the number of times other
people discover this for the first time and feel the urge to post it either
here or on Reddit. Not that I blame you at all, this is pretty amazing
stuff...

... but my count is 5.

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frognibble
I recommend the book "Parasite Rex" by Carl Zimmer for those who are
fascinated by this sort of thing. The book discusses several interesting and
creepy parasites.

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mih
This is as close as is gets in real life to the movie 'Alien'. Was Ridley
Scott inspired by this in some way?

~~~
mchouza
I believed that _Alien_ was inspired by _The Voyage of the Space Beagle_ , but
Dan O'Bannon (the screenplay writer) denied it: "I didn't steal Alien from
anybody. I stole it from everybody!"

<http://en.wikipedia.org/wiki/Alien_(film)#Origins>

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hristov
Yet there are still too many roaches out there.

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jfb
DO NOT WANT.

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joealba
I think I dated one of those in high school.

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terrapinbear
I, for one, welcome our new Emerald Cockroach Wasp overlords.

~~~
sliverstorm
So long as their stingers remain unable to penetrate the human skull or spinal
cord, we're safe. Once they figure out how to do that though, every man for
himself!

