Shakespeare's Butterflies: An Absence

Why are there no butterflies in Shakespeare? None, that is, beyond a few generic references to 'gilded butterflies', most notably Lear's 'so we'll live, And pray, and sing, and tell old tales, and laugh At gilded butterflies...' How was it that a poet so acutely aware of, and knowledgable about, the natural world, could discern butterflies - so beautiful, so various and so (then) abundant  - only in generic terms?
 Flowers, both wild and cultivated, are everywhere in Shakespeare, whose verse is the most beautifully flower-spangled in the language. There have been many studies of Shakespeare's flowers, and pictorial anthologies such as Walter Crane's Flowers from Shakespeare's Garden: A Posy from the Plays. More than fifty species are named in the works, along with forty-odd trees, and many 'Shakespeare gardens', on both sides of the Atlantic, have attempted to include them all in a suitably 'Shakespearean' setting. Birds too are abundant in Shakespeare - again some fifty-odd species, most of which Shakespeare clearly knew well - and indeed New York owes its starlings and house sparrows to a Shakespeare enthusiast's attempt to introduce 'Shakespeare's birds' to the New World.
 'Shakespeare's butterflies', however, simply don't exist. And he was entirely representative of his times in not discriminating between species of butterfly: it was a surprisingly long time before anyone - even (proto-)scientists - did. During Shakespeare's lifetime, there seem to have been no recognised names for individual species. The first book to include any recognisable descriptions (of some eighteen species) was being worked on by the pioneering Thomas Moffet, but did not see the light of day until long after Shakespeare's death.
 It was not until the great naturalist John Ray got to work that things advanced much further. In his Historia Insectorum (published in 1710), Ray described forty-eight species - but describe them was all he could do; there were no names for most of them. The description 'A large black butterfly with wings spotted with red and handsomely marked with white' (to translate from Ray's Latin) is clearly the Red Admiral, but no one, it seems, had yet called it that. Finally, in the early eighteenth century, James Petiver, 'the father of British butterflies', gave names to forty-nine species, including the Brimstone, the Painted Lady and a range of Hairstreaks, Admirals, Arguses and Tortoiseshells. Many of Petiver's names have subsequently been changed - his 'Hogs', for example, became 'Skippers', his 'Half-mourner' the 'Marbled White' - but finally Englishmen could talk about individual butterfly species, distinguish between them, and see them as something more than just 'gilded butterflies'.
 To return to John Ray, he wrote one of the most eloquent summaries of the magical allure of butterflies:
'You ask what is the use of butterflies. I reply, to adorn the world and delight the eyes of men: to brighten the countryside, like so many jewels. To contemplate their exquisite beauty and variety is to experience the truest pleasure. To gaze inquiringly at such elegance of colour and form designed by the ingenuity of nature and painted by her artist's pencil is to acknowledge and adore the imprint of the art of God.'
Shakespeare, I'd like to believe, probably experienced a similar delight in looking at butterflies - but, for once, he simply did not have the words.