Shawn Jemmett's 'please identify' mail

[Rebecca Jolly]

     Dear Shawn,
     
     I'm wondering if it is Hyalophora cecropia (Robin Moth?).  I have 
     been rearing some from eggs that I bought from a suppliers in the 
     UK.  The caterpillars looked a lot like the one you've found.  I 
     say 'looked' because they have now pupated, but I took some 
     photos and they look very similar.  I'm not certain about the 
     colour of the spiracles but mine seemed to change with every 
     instar!
     
     I have a query of my own which I shall take this opportunity to 
     post:  I haven't reared any silkmoths before and was wondering 
     how long they will remain as pupae.  It has been about five weeks 
     since they pupated and I am starting to get a little concerned 
     :-(
     
     Best wishes
     Rebecca Jolly