Saturday, September 22, 2012

The Wonder of the Fig
(Part 6- Of parasites and hyper-parasites)

In this part we'll look at the other actors revolving around the story of fig and their wasps. Not every relation between the fig and the wasps is purely based on mutualism. And this is where our free-loaders come in- the parasitic wasps that you see in the picture.

The female parasitic wasp, by definition, doesn't help the fig in pollination like the other wasps at all. Instead of entering the fig through the hole at the top, these parasitic wasps normally inject their eggs inside the fig with the help of the spectacularly long and thin hypodermic (adjacent pic) which is a very unique and specialised ovipositor. Once it bores its way through the fig, the tip of the hypodermic seeks out the little flowers in which eggs of the true, pollinating wasps have been laid. The hole she bores is again very impressive, on her scale, it's like drilling a 100-foot well. Males are often wingless, but winged males are also present. Inside the fig, these males of the parasitic wasps have savage pincer jaws which they only use for fighting- lacerating and slicing other males to death that they may encounter in their search of the female parasitic wasp eggs.

But that's not the end of parasitism; and whenever the female parasitic wasps drills a hole to lay her eggs, the hyper-parasitic wasps (parasite of a parasite) quickly use that already drilled hole to lay their own eggs down the hole!

Have a look at the parasitic wasp and its specialised and extra-ordinarily long ovipositor: http://www.zoo.ox.ac.uk/group/west/pics/fig_wasps.jpg (the one on the top-right is the parasitic drilling female wasp with that long ovipositor)

In our next parts, we'll look at more of such interesting stuff concerning other players in our story!

Sources:
1) ‘Climbing Mount Improbable’, Richard Dawkins, 1996
2) http://nirmukta.com/2012/08/17/the-wonder-of-the-fig/ (my article)
3) www.figweb.org
4)http://www.zoo.ox.ac.uk/group/west/StudyOrg.html

Image: http://www-tc.pbs.org/wnet/wp-content/blogs.dir/3/files/2008/08/gal23.jpg

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