http://www.ukbutterflies.co.uk/species. ... es=machaon
In addition, a new page has been added (under Species->Life Cycles->Larval Instars):
http://www.ukbutterflies.co.uk/species_ ... nstars.php
You can also see all of the gaps here (although a moderator will need to be told if you fill a gap, before this page updates, since the page is cached):
http://www.ukbutterflies.co.uk/species_ ... tage=larva
So the question is - would you find this useful, and what can be improved?
Oh - and why "Project Frohawk"? Aside from Frederick Frohawk being a personal hero, his seminal work, Natural History of British Butterflies, is a 2-volume masterpiece, with exquisite plates, and the culmination of 24 years (from 1890 to 1914) spent rearing all of the British butterfly species and documenting the findings in meticulous detail (publication was delayed due to the outbreak of war in 1914, and later by insufficient subscribers). The work has never been surpassed and "Frohawk", as it is lovingly known, is still actively referred to today, especially by those wanting to understand the development of the immature stages of the British butterflies. However, some of the early instar images are very hard to make out (since they are drawn life-size) and so perhaps we can add some clarity in heading toward Frohawk 2.0

Cheers,
- Pete