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

Doug Wechsler / Golden-backed snipe fly (Chrysopilus thoracicus) mating on Common milkweed leaf (Asclepias syriaca) Pennsylvania, USA, May.

Doug Wechsler / Common milkweed field (Asclepias syriaca) Morris Arboretum, Pennsylvania, USA, June.

Doug Wechsler / Large milkweed bug (Oncopeltus fasciatus) nymphs on Common milkweed (Asclepias syriaca) leaf, Pennsylvania, USA, August.

Doug Wechsler / Mating pair of Large milkweed bugs (Oncopeltus fasciatus) on Common milkweed (Asclepias syriaca) leaf, Pennsylvania, USA, July.

Doug Wechsler / Multicolored asian lady beetle (Harmonia axyridis) eggs and newly hatched larva on Common milkweed (Asclepias syriaca), Pennsylvania, USA, July.

Doug Wechsler / Great spangled fritillary butterfly (Speyeria cybele) two on Common milkweed (Asclepias syriaca), Pennsylvania, USA, June.

Doug Wechsler / Common milkweed (Asclepias syriaca), Todd Audubon Wildlife Sanctuary, Maine, USA, July.

Doug Wechsler / Acrobat ants (Crematogaster ashmeadi) nectaring on Common milkweed (Asclepias syriaca), Pennsylvania, USA, July.

Doug Wechsler / Milkweed / Oleander aphids (Aphis nerii) on common milkweed (Asclepias syriaca). Philadelphia, PA. August

Doug Wechsler / Large milkweed bug nymphs (Oncopeltus fasciatus) on common milkweed pod (Asclepias syriaca). Philadelphia, Pennsylvania, USA. July

Doug Wechsler / Caterpillar larva of Monarch butterfly {Danaus plexippus} on leaves of host plant Common milkweed (Asclepias syriaca) Adirondack Park, New York, USA

Thomas Lazar / Monarch butterfly (Danaus plexippus) caterpillar on Milkweed stalk {Asclepias syriaca}, Wisconsin, USA.

Thomas Lazar / Monarch butterfly (Danaus plexippus) caterpillar feeding on Milkweed leaf {Asclepias syriaca}, Wisconsin, USA.

Doug Wechsler / Hoverfly larva (Syrphidae sp.) and Aphids on milkweed leaf (Asclepias syriaca) Maryland, USA.

Larry Michael / Seed dispersal of Common milkweed {Asclepias syriaca} Wisconsin, USA

Doug Wechsler / Common milkweed seed pods {Asclepias syriaca} Philadelphia, USA

Philippe Clement / Seed pods of Common milkweed {Asclepias syriaca} Belgium

Doug Wechsler / Oleander aphid (Aphis nerii) alates and nymphs on Common milkweed (Asclepias syriaca) leaf, Pennsylvania, USA. July.

Doug Wechsler / Red milkweed beetle (Tetraopes tetrophthalmus) mating on Common milkweed (Asclepias syriaca), Pennsylvania, Philadelphia, USA. July.

John Cancalosi / Red milkweed beetles (Tetraopes tetrophthalmus) three on Common milkweed (Asclepias syriaca) mating pair and interloper, Maryland, USA.