The History of Butterfly Recording in Northamptonshire 1820-2011 details the history of butterfly recording in this county over the last 180 years and paints a stark picture of the number of species lost.
"What leaps out from this simple but fascinating book is the number of butterfly species that have been lost from this still largely rural county. Things didn't change too much during the Victorian era, but it still saw three species become extinct in the county – the black-veined white, the mazarine blue and the large blue. The loss of the later was attributed in part to over collecting. Since 1900 the losses have been more dramatic – down from 52 species in 1902 to 38 last year"
- Lester Cowling, Butterfly Conservation, Spring 2012