A Parasitic Wasp that Injects Its Venom Into a Cockroach’s Brain in Order to Control It

Daven Hiskey July 11, 2011 11
Jewel WaspToday I Found Out that the Jewel Wasp, also known as the “Emerald Cockroach Wasp”, is a parasitic wasp that injects various mind controlling toxins into a cockroach’s brain then leads the roach back to its burrow where its hatched larva ultimately slowly eat the still living cockroach’s body from the inside out.  So basically, a lot like my brother’s ex-girlfriend.

Specifically, the Wasp starts by stinging the cockroach around its midsection.  This temporarily paralyzes the roach’s front legs.  Now that the roach’s ability to move is slightly inhibited, the wasp makes a much more precise sting, injecting its venom into the part of the roach’s brain that controls its ability to initiate walking.

The venom injected into a specific part of the brain of the cockroach doesn’t actually affect the general motor skills of the roach.  At this point, it’s perfectly capable of fleeing, if it could be motivated to do so.  The problem is that the venom actually seems to inhibit the cockroaches desire to flee from potential danger and even pain, specifically by inhibiting the ability of the cockroach to begin complex behaviors, such as walking.  The venom does this by blocking a specific neurotransmitter called “octopamine”. Once they are coerced into moving, they can walk just fine, though they have trouble forcing their body to continue to move.

In any event, once the wasp has injected its venom into the correct part of the cockroach’s brain, the wasp is free to lead the roach back to a burrow by gently pulling on the antennae like a leash, which provides enough external stimulus to coax the zombiefied cockroach to walk, so long as the wasp continues to tug and guide it. Once in the burrow, the magic happens.  The wasp lays an egg on the roach’s abdomen.  It then exits the burrow and blocks up the hole.   The roach then sits around in the burrow seemingly without a care in the world.

About three days later, which is coincidentally about the same time the venom will begin to wear off, a little larva is hatched and proceeds to feed on the delectable roach.  But the fun doesn’t stop here.  The larva doesn’t actually eat all the roach right away.  No, the roach is still quite alive when the baby wasp chews into its abdomen and proceeds to live there as a parasite.  Over the next week or so, the larva eats the roach’s internal organs generally in such an order that the roach will stay alive for quite some time (four or five days).  Once the larva has eaten all the innards of the roach and the roach dies, it then forms a cocoon inside the cockroach’s body from which a full grown wasp eventually emerges.

Bonus Facts:

  • Interestingly, when researchers remove the part of the cockroach’s brain that the wasp normally stings (the sub-esophageal ganglia), which handles boosting the signals that cause the cockroach to walk, among other things, the wasp will continually sting the cockroach for as much as 3 minutes in various spots, trying to find the sub-esophageal ganglia.  Normally, it takes the wasps only around 15 seconds to locate and sting the correct spot.  If the sub-esophageal ganglia is left in, but the nerve is cut, it fools the wasps and they only take that 15 seconds or so to locate the correct spot, like normal.
  • Researchers have actually successfully created an antidote for the Jewel Wasp’s venom, which allows the cockroach to exhibit more normal behavior after being stung.  Further, they also have found that if other areas of the cockroach’s brain are injected with the Jewel wasp’s venom, even those areas around the sub-esophageal ganglia, it seems to have no major effect on the cockroach.
  • With only one mating session, the female Jewel wasp will have enough fertilized eggs to place an egg on several dozen cockroaches.
  • It is a myth that cockroaches would be able to survive an extreme nuclear fallout.  For more on this click here.
  • Jewel wasps typically live for several months and can be found in various tropical regions in Africa, India, and the Pacific Islands.

Expand for References:

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11 Comments »

  1. Michiel van der Ros July 11, 2011 at 7:03 pm - Reply

    “So basically, a lot like my brothers ex-girlfriend.” Laughing my ass off!

  2. Loren Gamble July 12, 2011 at 8:22 am - Reply

    Your material is always interesting, but please, please learn the difference between “its” and “it’s.”

    • Daven Hiskey
      Daven Hiskey July 12, 2011 at 11:16 am - Reply

      @Loren Gamble: My bad. At 4am it seemed like a good idea to use “it’s” as in using the apostrophe there to show possession, not to indicate “it is”. Upon further thinking about it after a good night’s rest, I’m not really sure why I thought that oh so briefly, as “its”, like hers, his, yours, and the like, by itself shows possession. :-)

  3. Ahmad July 12, 2011 at 1:02 pm - Reply

    And, of course, this mechanism just evolved randomly over zillions of years no?

    We start off by a wasp stinging roaches at random points for no purpose whatsoever. Then a genetic mutation comes up with a modified wasp which, for some reason, feels inclined to sting them at the center of their motor nervous system. And soon enough we have one secreting an octopamine-inhibitor specifically at the second sting. Oh, and it also coincidentally feels like leading the roach to its burrow afterwards, and also happens to want to lay its eggs on it by that time. It doesn’t know why, it just does.

    Moreover, the baby wasp doesn’t enjoy chewing parts of the roach which would kill it immediately. No, it simply finds the ones which would keep it alive for as long as possible the most tasty. Just a simple Darwinian coincidence.

    Makes perfect sense.

  4. nlconway October 25, 2011 at 1:39 pm - Reply

    Beware the Jewel Wasp! “SUPER EVOLVER” Should we be scared?

  5. Katlen January 26, 2012 at 9:08 am - Reply

    “So basically, a lot like my brother’s x-girlfriend” Hahaha!!

  6. the dude August 8, 2013 at 3:10 pm - Reply

    While it’s funny, I could really do without the ‘like by brother’s x-gf’ part. It just ruins the perfectly informative and professionally written article.

    • Yer Pal October 25, 2013 at 6:43 am - Reply

      The rod up this mans butt has got a rod up its butt!

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