01 December 2011

The fairy wasp and its tiny, tiny brain

The fairy wasp in the image above is pictured next to a Paramecium and an amoeba; note that it is smaller than unicellular organisms.
[Alexy] Polilov found that M.mymaripenne has one of the smallest nervous systems of any insect, consisting of just 7,400 neurons. For comparison, the common housefly has 340,000 and the honeybee has 850,000. And yet, with a hundred times fewer neurons, the fairy wasp can fly, search for food, and find the right places to lay its eggs.
On top of that Polilov found that over 95 per cent of the wasps’s neurons don’t have a nucleus... As it changes from a larva into an adult, it destroys the majority or its neural nuclei until just a few hundred are left. The rest burst apart, saving space inside the adult’s crowded head...
Further details at Ed Yong's Not Exactly Rocket Science, via Neatorama.  The topic interested me because I've always wondered how a Monarch butterfly had enough neural capacity to not only fly and feed and reproduce, but to navigate from my yard to the mountains of Mexico.  Apparently they have several hundred thousand neurons - but it's still awe-inspiring for me.  You learn something every day.

And before leaving for the day, let's post an immense insect eating a carrot -


It's a weta found on Little Barrier Island, New Zealand - one of the Pictures of the Day in The Telegraph.  Credit: Mark Moffett/Minden Pictures/Solent

2 comments:

  1. 7,400 neurons in an insect smaller than a single celled amoeba? How many cells comprise the rest of its skeletal framework? How small do cells get? Thanks for stretching the old neurons a bit.

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  2. Hey, c'mon! Its brain may be tiny, but it's bigger than the average politician's!

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