www.ukbutterflies.co.uk

more photos

emerging from pupa:

http://www.youtube.com/watch?v=xhdzIRgN464[/video]

That's a great sequence Dean .
It looked like quite a struggle for the emerging adult. Others I have observed (like Orange Tip) just slide out without any fuss. You can really see the butterfly pulsing its abdomen to initially split the pupal case and then fight its way free. Another interesting detail is that this species seems to deposit its red-coloured metabolic waste product (meconium) into the empty pupal case as it leaves. All other species that I have seen emerging leave the pupal case dry and expel the fluid outside as they expand their wings. I'm not absolutly sure but I suspect that they can also expel it as a defensive mechanism if they are disturbed by a preditor during this vulnerable stage of their development.

Vince

Good observations Vince!

First I thought it was so hard for him to emerge because it was a colder morning. I thought it hasn't enough energy to do it faster, but all other butterflies emerged almost in the same way. They all voided meconium in the same moment. I think it is partly because Scarce Swallowtails have relatively larger abdomens in comparasion with other butterflies, so they eject part of meconium to become "smaller" to ease emerging. They also voided part of meconium after wings were fully opened like other species.

I agree with you it can be a good defensive mechanism during that vulnerable stage. Therefore they keep it up inside their bodies till the moment they are ready to flight and escape predatores.