The Monarch caterpillar feeds almost exclusively on MILKWEED.
This plant owes its name to its milky sap, which contains toxic substances. However not all milkweeds secrete that sap, as we will see below, and the toxicity levels vary across the species. In addition, insects (such as the Monarch caterpillar) that feed on milkweed have developed protections against those toxins.
The Latin name of this plant genus is ‘Asclepias’, from Greek ‘Asclepius’, the God of healing. This is because some species have medicinal properties.
We will examine three milkweed species below that grow in Eastern Canada and the United States – Swamp Milkweed, Butterfly Milkweed, and Common Milkweed, and compare their features.
SWAMP MILKWEED (Asclepias Incarnata)
BUTTERFLY MILKWEED (Asclepias Tuberosa)
COMMON MILKWEED (Asclepias Syriaca)
COMPARISONS BETWEEN THE 3 MILKWEEDS