Enter the hyperparasites – wasps that lay eggs in wasps that lay eggs in caterpillars

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A very hungry caterpillar munches on a cabbage leaf and sets off an alarm. The plant releases chemicals into the air, signalling that it is under attack. This alarm is intercepted by a wasp, which stings the caterpillar and implants it with eggs. When they hatch, the larval wasps devour their host from the inside, eventually bursting out to spin cocoons and transform into adults. The cabbage (and those around it) are saved, and the wasp—known as a parasitoid because of its fatal body-snatching habits—raises the next generation.


But that’s not the whole story.

Some parasitic wasps are “hyperparasitoids”—they target other parasitoid wasps. And they also track the cabbage’s alarm chemicals, so they can find infected caterpillars. When they do, they lay their eggs on any wasp grubs or pupae that they find. Their young devour the young of the other would-be parasites, in a tiered stack of body-snatching. It’s like a cross between the films Alien andInception.

Erik Poelman from Wageningen University in the Netherlands studied one of these grisly networks: the caterpillars of the small cabbage white butterfly are attacked by two parasitoid wasps—Cotesia rubecula and Cotesia glomerata—which in turn are attacked by the hyperparasitoid Lysibia nana.

L.nana lays one egg in every wasp grub or pupa that it finds. C.rubecula produces a huge grub, but it only lays one in each caterpillar. C.glomerata is the better choice for a host—its smaller larvae offer less room for L.nana’s own progeny, but it implants around 20 to 40 of these into the same unfortunate caterpillar. If L.nana can find one of these clusters, it can parasitise an huge brood of wasp larvae in one visit. And it can find them thanks to the cabbage.

Written By: Ed Yong
continue to source article at blogs.discovermagazine.com

13 COMMENTS

  1. I can’t open the link to the main article (not sure why) but the opening paragraphs are already deeply disturbing. In the larger sense, the whole biosphere is a roiling mass of predation. Sometimes I marvel at the fact that I have managed to stay alive in the midst of it all (especially when I am recovering from a cold.)

    Cabbages have an alarm system? 

  2. There is a terrible but largely unnoticed war raging between animals, plants and insects which makes perfect sense in the illuminating reason of evolution and makes no sense at all if it is explained by the idea of a ‘God who so loved the world………….that he filled it with nightmares too horrible to comprehend.’

  3. And the amazing thing is that none of this happened until 6000 years ago when the only 2 humans around ate a bit of fruit.

    But seriously, RD put it beautifully in “River out of Eden”

    The total amount of suffering per year in the natural world is beyond all decent contemplation. During the minute that it takes me to compose this sentence, thousands of animals are being eaten alive, many others are running for their lives, whimpering with fear, others are slowly being devoured from within by rasping parasites, thousands of all kinds are dying of starvation, thirst, and disease. It must be so. If there ever is a time of plenty, this very fact will automatically lead to an increase in the population until the natural state of starvation and misery is restored. In a universe of electrons and selfish genes, blind physical forces and genetic replication, some people are going to get hurt, other people are going to get lucky, and you won’t find any rhyme or reason in it, nor any justice. The universe that we observe has precisely the properties we should expect if there is, at bottom, no design, no purpose, no evil, no good, nothing but pitiless indifference”

    SG

  4. In the hope that this thread attracts not wasps but expert entomologists, can anyone identify this foul creature which I videoed in Etosha, Namibia? 
     
    http://www.youtube.com/watch?v
     
    I think it’s a parasitising wasp, scurrying away with its much-larger paralysed prey, but it doesn’t look like a (usually skinny and distinctive) member of the Ichneumonidae.
     
    For years I’ve tried to find out precisely which one of God’s creatures this is.

  5. @rdfrs-ca2de931da459a1e23803a3182e55686:disqus Plants have alarm systems!  Many of the plants signals are, in fact, gases.  They generate these gases in response to different stimuli.  One, ethylene (a plant hormone), is released by plants and causes fruit ripening.  This is how a plant coordinates parts of  it’s life cycle.  Other gases are released in response to the plant being eaten.  This signals plants around it to stimulate production of “anti” being eaten chemicals….

    It gets even better.  Up to 90% of flowering plants (angiosperms) have an affiliation in their root systems.  This affiliation is with certain types of fungi known collectively as mycorrhizae.  These mycorrhizae grow in mats under the surface of the ground and they interface with plant root hairs.  When the plant is in distress, chemicals are made internally that leech downward through the plant roots and into the fungi that sit surrounding the plant root system.

    This chemical, now in the fungi, diffuses cell to cell and gets “delivered” to neighboring plants by virtue of their roots being in contact with the same fungi that affiliates with the initial plant.  So, when you are walking through the woods, plants are communicating, invisibly, under your feet and around your head!!!!!!

    Fucking EVOLUTION!!!!!!!

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