Early English Watercolour of Butterflies

Watercolour on pith paper laid down on card depicting a white butterfly with a Delias nigrina (Black Jezebel).  The words "September Visitors Candidates for Orange Blofsoms" written in sepia ink on back of card.  The use of the "long s" which looks like an f, used to spell Blossom, stopped being in use by the end of the Georgian period.  circa 1800-1820, English
Frame size:
Length 17cm
Width 16.5