I looked up 'Life Cycle', under 'Biology' on this site, and was met with the message 'Coming Soon' so, Pete, please include this information when you write this bit up
![Smile :)](./images/smilies/icon_smile.gif)
The first (American)site I found on Google confused me further by stating: "Caterpillars go through 5 stages of growth. Each stage is called an 'instar.' ... As a caterpillar grows, it 'molts' 5 times before it becomes a chrysalis." Well, 5 moults means six intervening stages from egg to pupa, by my reckoning. Also, it transpired that the article was specifically about the Monarch. Elsewhere, I read that the Red Admiral has four instars. I looked through my fairly extensive library: most books only cover the adult stage in any detail. Thomas & Lewington simply states 'several' stages for the caterpillar and I couldn't see anything at all on the subject in Jim Porter's 'Caterpillars'.
So please, all you experts who breed butterflies - what's the answer?