Chinese Three-tailed Swallowtail_16-06-05_Bhutanitis thaidina
Bhutanitis thaidina, commonly known as the Chinese Three-tailed Swallowtail, is a rare species of butterfly in the family Papilionidae. The butterfly is found in Tibet and China. The larva feeds on Aristolochia moupinensis. Wikipedia. The food plant is a climber with spectacular flowers and is itself restricted to China.
Rilong, Sichuan, China.
A tricky exposure - a black butterfly on a white flower.
Thanks to sunwenhao90 for the ID.