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the Fly ( story of a parasitic wasp )

Updated: Sep 28, 2020

Do you remember the famous Hollywood science fiction movie ‘The Fly’? In that the actor invents some computer programme, constructs a capsule and gets teleported to other capsule. Now you must be wondering how this movie is any way related to butterfly story?

Well, actually, whenever I used to see any caterpillar turning into pupa at my terrace garden, I used to think of that movie scene. Only thing was that, instead of teleportation, here the caterpillar makes a capsule and gets transformed into totally different morphological figure within a few days – ‘A complete makeover’. I always admired this miracle by nature of transforming a wriggly looking caterpillar to vibrant, colourful and highly active adult butterfly. And one day something strange happened ….


Few years back I was having a tailed jay caterpillar on champa at my terrace garden. The caterpillar grew well and as expected pupated. The pupa was under the leaf hiding from usual garden birds like mynas, bulbuls and tailor birds. Everything was as usual.

Although I had observed many pupas and eclosings, every time it gives me same thrill, enthusiasm and excitement. Every day I used to observe the pupa to check for colour change. And one day the colour changed to blackish brown. But this change was a bit different than I had observed in the past. This was hazy and patchy and there were no wing patterns and dark colour of eyes. There was some problem! But what was that?

Now, I recollected the movie, where, when there occurs a problem the actor rechecks the sequence in the computer. I had no such option to rewind the whole sequence and check the fault. But still working on computer I googled various sites like Wikipedia and also checked on WhatsApp. And I got the fault. The sites told me that the pupa has been parasitized.,


I couldn’t understand. How come normally growing healthy caterpillar which turned into a normal looking pupa got parasitized. That was my second question. Now every thing was going exactly as per the movie scenes.


The google and other friends responded that during caterpillar stage the parasitic wasp lays eggs in the caterpillar. The wasp eggs hatch inside caterpillar’s body and young wasp larvae start eating the caterpillar from within sparing vital organs. So externally caterpillar looks normal, grows normal and also pupates.


Now what? I typed again. I was like the film hero. I was totally confused and not able to understand what and how things went wrong in the sequence. And the reliable sources were giving me instant information.


The answer came as, now the parasitic larva will pupate inside the pupa and then will emerge as adults by piercing through the butterfly pupa. And the butterfly will be dead now. I started feeling giddy, I read it again n again. And tried to understand the meaning. The thing was that there were wasp pupas in the butterfly pupas and now instead of butterfly, few wasps will be emerging out of that butterfly pupa.



Really shocking and very new to me. Never I had imagined or seen such thing before. But nature is full of surprises, and challenges. Nothing is easy and rosy. It is fight for survival and survival of the fittest.


Now only thing to be done was to wait and observe which I continued with same excitement. And within next two days it happened. And I observed that event which google had told me. The tailed jay pupa developed two three holes and small black coloured wasps started emerging out of it. After settling briefly on the pupa and getting their wings ready they flew away. May be after mating they will find another such juicy caterpillar to lay the eggs and continue the life cycle. Within 10-20 minutes more than dozen wasps emerged out of that pupa.


The pupa was now looking empty and I checked closely and inside the pupa were wasps’ pupas and shrivelled body of developing butterfly. The clever wasps made it sure not to kill their host till there development is complete.


That movie also has a twist in the story, where, accidentally a fly enters the capsule and gets genetically incorporated with the actor. And then starts all the science fiction.


Something similar happened at my terrace garden. The clever wasp laid eggs into the growing caterpillar. The caterpillar unaware of it continued to grow and pupated. But in mean time the wasp larvae also grew faster and pupated ultimately killing the butterfly caterpillar and emerged out of pupa like capsule as adult wasps.


This was the first of an experience for me at my terrace garden. And just like the movie this experience was equally thrilling, surprising with dramatic finish. But this was not a fiction but a real natural event between parasite and a host and luckily, I was the prime witness, sitting in the front row to watch all the drama getting unfolded from start to finish.




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