Thanks for that, Dave - the web page you linked to was an interesting read.
For what it's worth, I have just spent about an hour writing down phonetic transliterations of the way I, personally, pronounce the Latin names of English butterflies, using an entirely non-standard phonetic scheme that made sense to me at the time but probably to no one else. I have posted it here: http://www.guypadfield.com/pronunciation.html
I'm definitely not
suggesting I'm right - in fact, I know I'm not, because it's all very inconsistent. But this is how I do, actually, pronounce the names when I talk to my dog. It might prompt someone who knows more than me into doing a better job...