Michael & Patricia Fogden / Monarch (Danaus plexippus) butterfly, feeding on Scarlet Milkweed (Asclepias curassavica) in the cloud forest, Costa Rica

Michael & Patricia Fogden / Passionvine Butterfly (Heliconius clysonimus) attempting to feed at Crucifix Orchid (Epidendrum radicans) the original mimics Lantana sp and Asclepias curassavica but provides no nectar

Nick Upton / Shrubby milkweed (Gomphocarpus fruticosus), invasive species native to South Africa. Beside Rio Codula di Luna stream, Gennargentu National Park, Dorgali, Sardinia. June.

Heather Angel / Leopard lacewing (Cethosia cyane) nectaring on Tropical milkweed / Bloodflower (Asclepias curassavica). Yunnan, China.

Derek Galon / Caterpillar of Monarch butterfly (Danaus plexippus) feeding on seed pod of Bloodflower plant ( Asclepias curassavica). Dominica, Eastern Caribbean, Lesser Antilles. Focus stacked photo.

Derek Galon / Seeds of Bloodflower plant (Asclepias curassavica) blown by wind from their pod. Dominica, Eastern Caribbean, Lesser Antilles. Focus stacked photo.

Joao Burini / Milkweed (Asclepias mellodora), Intervales State Park, Sao Paulo, Atlantic Forest South-East Reserves, UNESCO World Heritage Site, Brazil.

Doug Wechsler / Milkweed tiger moth (Euchaetes egle) caterpillars on Common milkweed (Asclepias syriaca) Philadelphia, Pennsylvania, USA, July.

Doug Wechsler / Megachilid bee (Megachilidae) on butterflyweed (Asclepias tuberosa) French Creek State Park, Philadelphia, Pennsylavania, USA

Ingo Arndt / Caterpillar larva of Monarch butterfly (Danaus plexippus) on Milkweed leaf (Asclepias sp), USA

Ingo Arndt / Egg of Monarch butterfly (Danaus plexippus) on the underside of Milkweed leaf (Asclepias spec) USA

Ingo Arndt / Monarch butterfly (Danaus plexippus) egg (approx 1mm) on the underside of a Milkweed leaf (Asclepias sp), USA