Butterflies

[Ember]

I am curious as to how a soft vulnerable butterly emerges from its chrysallid. It has no teeth to bite its way out, it would damage its wings if it tried to batter its way out. I bet you know the answer N.F.

[New Forester]

If I remember rightly it sort of bursts its way out. Fluid pressure builds up, and it wriggles so as to pull its legs and wings out of their cases. The chrysalis splits along the back, and it keeps on wriggling to get out. If you look at the chrysalis you can see that the legs, wings, tongue and antennae are all arranged stretched out straight, pointing away from the split. Other insects do it in a simlar way. Flies have help from an inflatable bladder on their heads which fills with fluid to break a round lid off the hard pupal shell. If you squeeze a fly very gently, sometimes this bladder pops out.

[FP]

'If you squeeze a fly very gently, sometimes this bladder pops out.' Ugh!

[Ember]

NF thank you for your answer for some reason I cannot rate it but consider you have three stars. However one question now where does the fluid come from for the pressure to build up. Nature is amazing isn.t it!