Celastrina argiolus - Holly Blue - Boomblauwtje - Faulbaum Bläuling
The male upperside is bright violet-blue. The female upperside is sky-blue with black borders. The underside is very pale blue with black spots. Holly is the main foodplant for the caterpillars, although Dogwood, Spindle, Gorse, Bell Heather, Brable, Raspberry, Hap and Ivy may be used. The Holly Blue is a common butterfly which can be often found in gardens, parks, heath and woodlands.
From egg to butterfly 2015:
From egg to butterfly 2016/2017: