- July 19, 2023 - Insectarium : Mission Monarch
Every year we impatiently look forward to this moment: the arrival of the majestic monarch butterfly. But did you know that there are a number of other butterflies that look like it? Discover the insects that are sometimes confused with the monarch.
The milkweed tiger moth caterpillar
Grey and slightly hairy at the beginning of its life, the milkweed tiger moth caterpillar (Euchaetes egle) shares the monarch’s host plant, the milkweed. Unlike the monarch caterpillar, which is rather solitary in nature, the milkweed tiger moth caterpillar lives in groups. Dozens of them can be found nibbling on milkweed leaves.
The black swallowtail caterpillar
The black swallowtail caterpillar (Papilio polyxenes) has different dietary preferences from the monarch’s. This lepidopteran loves plants in the umbellifer family (parsley, celery, carrot, fennel…). So it’s normal to find this caterpillar in your garden if you’re growing those plants. The black swallowtail caterpillar is pale green in color and presents black bands with yellow or orange dots. The monarch, meanwhile, has yellow, white and black stripes.
Moreover, unlike the monarch caterpillar, the black swallowtail has no filaments near the head or at the end of the abdomen. It nevertheless has an orange fork-shaped organ called an osmeterium located near the head that the caterpillar deploys when it feels threatened.
The viceroy
The viceroy (Limenitis archippus) is the butterfly most easily confused with the monarch. This monarch lookalike is present from central to eastern Canada. The viceroy, which measures about seven centimeters, is smaller in size than the monarch. It also displays a black line that crosses the veins on its back wings.
The painted lady
The painted lady (Vanessa cardui) is the most widespread butterfly species in the world. Just like the monarch, it’s a migratory species with orange wings. However, the painted lady does not present black veins, but black and white patches instead. On the rear of its back wings, it sports pale colors and a row of eyespots. The painted lady’s flight is fast and intermittent, unlike the slow fluttering of the monarch.
Polygonia
Polygonia are a genus of butterflies in the Nymphalidae family. Most of the species in this genus have orange wings. However, unlike monarchs, polygonia have irregular shapes and lacy wings. Sightings of the eastern comma (Polygonia comma) in Canada are synonymous with the arrival of spring.
Would you like to have a visual support to help you differentiate the monarch from other butterflies? An identification fact sheet exists that will assist you in properly identifying them. Consult it and report your monarch observations on the Mission monarch site. That way you’ll contribute to the safeguarding of this emblematic species!