What is it?

[MagritAsh at aol.com]

I have five passiflora vines in my garden each is a different variety.  There 
are many Zebra Longwing and Gulf Fritillary visiting the garden and 
depositing eggs.  A n large number of eggs are deposited on the younger 
leaves but I hardly find any caterpillars for the number of eggs seen.  I 
took a cutting with many eggs to observe, kept them on a humid closed 
chamber.  The caterpillar came out and when they were about 4 mm they 
appeared to just disappear.  I thought at first they somehow got out, so I 
repeated with another cutting and kept a closer look.  I found they actually 
disintegrated to just a few drops of powder like material.  So what is it?.  
Can any one shed some light?   
Thanks
Margarita (email:magritash at aol.com)