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Miranda Hodgson

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Parasitic wasp larvae take contol of caterpillar

Posted by Miranda Hodgson on 22 Oct 2010 at 11:32 AM

If you’re squeamish, look away now because the subject for this blog may be somewhat unpleasant. I’ve touched before on parasitic wasps (mainly of the species Aphidius) and how they lay their eggs in aphids, which develop inside the aphid and then chew their way out, just like in the film ‘Aliens’. I discovered that little gem after looking at a parasitised aphid through a small microscope and you could see the jagged exit hole. I wish I’d taken a photograph, but I didn’t, so this one of a parasitised aphid where the larva is yet to emerge will have to serve.

Some time after seeing the parasitised aphid, I came across another type of parasitic wasp (Apanteles glomeratus), one that lays its eggs in caterpillars. Not just any old caterpillar either, but the caterpillars of cabbage white butterflies. They are mainly seen in September and October, but you can still find a few about. Look out for what appears to be yellow, woolly fluff attached to an unmoving caterpillar and look closely. It isn’t fluff, it is the cocoons protecting the wasp larvae. What is even stranger is that the parasitised caterpillar actually helps out by staying close to the larvae and seeing off predators, until it finally dies of starvation.





Looking further, I found a film clip showing just what goes on inside the caterpillar, how it is controlled, and then what happens once the larvae emerge. It might make you go ‘Eeewwww!’ but it’s fascinating to see what goes on in our gardens, right outside the back door. And, how did they get the camera inside the caterpillar?


richardpeeej said:

I found this read so very interesting Miranda and the film clip although gruesome was fascinating. You have taken some really good photographs here too. Thanks for sharing, I always enjoy reading your nature blogs.......Richard

on 22 Oct 2010 at 12:16 PM

Miranda Hodgson said:

Thanks Richard! I'm so glad that you find these things interesting as well :-)

on 22 Oct 2010 at 04:39 PM

asj said:

As usual, Miranda, brilliant and informative blog.  However I think you should warn people not to watch the film clip while eating - 'Eeewwww!' is not enough!!!  How did they get the camera inside?

Cheers    asj

on 22 Oct 2010 at 04:42 PM

David Benson said:

Eeewwww, indeed! The clip is astonishing. Barely seems possible! Thank you for drawing my attention to these appalling goings-on. xx

on 22 Oct 2010 at 05:01 PM

Miranda Hodgson said:

Thanks, both! Know what you mean, asj. It took me a few minutes to click 'play' on that clip.

David, thought you'd appreciate it!

on 23 Oct 2010 at 02:08 PM

EvaInNL said:

I'll take your Eewww and raise it with a Yuuughckkk + Gag + Quick closing of window. That truly made my skin crawl. But I want some on my lotty. :o)

Scarey but brilliant post Miranda!

on 24 Oct 2010 at 10:22 AM

Miranda Hodgson said:

Thanks, Eva! Yes, it is a bit grisly. Interesting to see what goes on, though!

on 25 Oct 2010 at 11:53 AM