Swallowtail butterflies are seen pollinating a patch of West Indian lantanas along a road in Chun'an county, Hangzhou city, east China's Zhejiang province, on Sept 12. [Photo/CFP]

The swallowtail belongs to the Papilio genus. It is widely distributed in the Northern Hemisphere. It flies from March to September at lower elevations. For areas at higher elevations, it only appears in short summers. [Photo/CFP]