Celastrina argiolus
The holly blue (Celastrina argiolus) is a butterfly that belongs to the lycaenids or blues family and is native to Eurasia and North America.

The holly blue has pale silver-blue wings spotted with pale ivory dots. Seitz describes it "Male above shining violet blue, only the apical portion of the costal margin being minutely edged with white. The female has both wings broadly bordered with dark, the margin of the hindwing bearing vestiges of ocelli. Underside silver-white, in the disc a row of black dots, some of which are elongate, and before the margin blackish shadowy dots.