Common Milkweed Pollinators

There are 15 species of milkweeds in the Chicago area.  The genus name, Asclepias is named after the physician Aesculapius, the son of Apollo, who studied medicine under Chiron, a centaur in Greek mythology of great wisdom and knowledge of medicine.  The common milkweed, Asclepias syriaca is found in several different habitats that all have plenty of sun and disturbed soils.  These areas include old fields, pastures, remnant prairies, fens and along roadsides and railroads.  This species and several other milkweed species are favorite plants in backyard gardens.

Common milkweed supports many insects and pollinator species.  All parts of the plant are used for food including nectar, pollen, foliage and stems.  Several species also breed on common milkweed, laying eggs in flowers where larva can feed on nectar and later move to feed on foliage.

Nectar provides food for 14 species of butterflies, four beetles, one weevil, six plant bugs, eight ants, 41 bees, six wasps, and six flies.  The bees, wasps and flies also eat the pollen as do an additional ten beetles, three  weevils and two ant species. 

Black Swallowtail Butterfly, Eastern Tiger Swallowtail Butterfly, Monarch Butterfly, bees in the Andrena genus, and Hummingbird Moths are some of the more common insects that you can observe on milkweeds.

All of the bees, wasps, and flies mentioned above plus ten beetle species, three weevils, and two ant species gather pollen from the flowers.

Milkweed foliage is food for three beetle species, one earwig, one leaf miner, and one weevil.  The foliage also supports seven species of aphids and their symbiotic partners, ten ant species.  The aphids feed on the common milkweed stem and leaves, then produce a sweet substance that the ants use for food.  In return, the ants provide protection from predators for the aphids.

Observing the many species of insects using this one plant throughout the day is fun and interesting.  Many other milkweed species and insect groups are also found in our area.  Take along a camera or hand lens on your next walk and watch closely to see all of the activity!