Juergen Freund / Timelapse of a Cairns birdwing (Ornithoptera euphorion) butterfly caterpillar metamorphosing into a chrysalis, Queensland, Australia, April.

Piotr Naskrecki / Large Striped Swordtail (Graphium antheus) butterflies, Gorongosa National Park, Mozambique

Ralph Martin/ BIA / Oldworld Swallowtail (Papilio machaon) wing, Baden-Wurttemberg, Germany

Ingo Arndt / Close-up of wing detail of Emperor swallowtail butterfly (Papilio ophidicephalus) Africa

Ingo Arndt / Lemon / Common lime swallowtail butterfly (Papilio demoleus) on flower head, Asia, Captive

Peter Schwarz/ BIA / Oldworld Swallowtail (Papilio machaon) butterfly, Hesse, Germany

Pete Oxford / Thoas Swallowtail (Papilio thoas) butterfly, Mindo Cloud Forest, Ecuador

Jussi Murtosaari / Apollo butterfly (Parnassius apollo) in flight, Foglo, Ahvenanmaa / Aland Islands, Finland, July.

Silvia Reiche / Oldworld Swallowtail (Papilio machaon) caterpillar on fennel, Netherlands

Thomas Marent / Citrus Butterfly (Papilio demodocus) drinking minerals and salts from soil, Jozani National Park, Zanzibar, Tanzania

Jussi Murtosaari / Mountain Apollo (Parnassius apollo) in flight, southwest Finland, February, July.

Jussi Murtosaari / Mountain Apollo butterfly (Parnassius apollo) male flying across road, Aland Islands, Finland, July.