Swallowtail butterfly, alighted on a fragrant blossom of lilac, a very popular ornamental bush, which bloom in the spring and early summer. 'Swallowtail' butterflies are large and attractive butterflies in the family Papilionidae, and include over 550 species, which inhabit every continent except Antarctica. Theirs larvae are feed on plants of the citrus, and are considered pests in citrus orchards. The family includes also the largest butterflies in the world, the 'Birdwing' butterflies, which are cultivated in farms for the purpose of collectors.