Rare moth in severe decline at its last English site

Numbers of a rare species of moth -- found only in York in England -- have tumbled in recent years, a team of scientists has discovered. The Dark Bordered Beauty moth is found on Strensall Common, an area of protected lowland heath near York. This is the last known English site for the moth, although there is a handful of populations in Scotland, where the moth is also rare.The Dark Bordered Beauty moth, Epione vespertaria (Formerly known as Epione paralellaria) is similar in appearance to the more common Bordered Beauty moth (Epione repandaria), but the purplish border on the forewing is of even width; in the Bordered Beauty, the outer border tapers sharply towards the tip of the wing. The sexes are different in appearance; males are darker and more orange in colour than the pale yellow female.
Sources:
Science Daily, 22 June 2016
https://www.sciencedaily.com/releases/2016/06/160622144812.htm
Arkive
http://www.arkive.org/dark-bordered-beauty-moth/epione-vespertaria/