Identification Tips
Helpful Tips to Identify Monarchs at Any Stage of Development
For a quick guide you can print to take with you in the field, see our "Identifying Monarchs by Life Stage" resource.
MONARCH LIFE CYCLE
From egg to butterfly, it takes the monarch between 21-33 days to go through the metamorphosis process. The warmer the temperature outdoors, the more quickly the process happens.
The eggs are laid on milkweed, typically on the underside of the leaf. The developing caterpillar consumes the milkweed until it is ready to pupate, or form the chyrsalis.
Once emerging from the chrysalis, the lifespan of the adult monarch depends on whether it is of the breeding generation (five to six weeks) or the migratory generation (eight to nine months).
For more photos and an amazing video developed by National Geographic showing the complete process, click HERE.
LOOK-A-LIKES: Orange is the new black. Let this hint help you remember that monarchs are orange and black, not yellow and black like the swallowtails we see more frequently. Other butterflies mistaken for monarchs that occur in Utah are shown below. For more photos, click HERE.
Monarch butterfly (female)
Monarch butterfly (male - notice the dark spots on the hind wings)
Western tiger swallowtail
Painted lady (smaller than a monarch)
Viceroy (notice the diagonal black lines on the hind wings) Photo by Becky Yeager
Queen butterfly
EGGS: Monarch eggs are usually found on the underside of a milkweed leaf and are a creamy yellow in color. They are cone shaped with vertical ridges. In contrast, milkweed leaves "bleed" many little stark white latex pearls that can fool you into thinking they are eggs (as in the photo on the right). They are usually found along the veins of the leaf, but can appear anywhere.
Monarch eggs can be found on tender milkweed seedlings, that grow along the edges of a milkweed patch.
Monarch egg
NOT monarch eggs. These are droplets of the "milk" from the milkweed plant.
CATERPILLARS: Signs of tiny monarch caterpillars eating the surface level of the leaf are usually accompanied by dark frass (poop). The larger the monarch caterpillar, the larger the frass.
The consumption of the milkweed results in holes that go all the way through the leaf. Other damage to a leaf isn't as defined and lacks frass. Seed pods are also occasionally consumed by monarch caterpillars.
During the heat of the day, the caterpillars often move to the base of the plant.
Monarch caterpillars are black, yellow and white (except for right after they hatch). The closest look-a-like is the Queen butterfly caterpillar, which is rarely seen in Utah. For more help identifying monarch caterpillars, click HERE.
Newly hatched caterpillar and frass (caterpillar poop).
Various sizes caterpillars and how they eat the leaves.
Damage to milkweed leaf from hail. NOT caterpillar-related.
Damage to milkweed leaf that is NOT caterpillar-related.
Monarch caterpillar (late stage known as the 5th instar)
Queen butterfly caterpillar (NOT a monarch caterpillar)
CHRYSALIS: A monarch chrysalis can typically be found on the same milkweed plant that supported the caterpillar throughout it's growth. However, a caterpillar can wander to adjacent plants or structures to find that perfect protective spot. The appearance of the chrysalis is green but turns dark soon before the monarch is ready to eclose (emerge).
Chrysalides (chyrsalis, plural) in various forms. The monarch chrysalis has a green appearance for 12-16 days and then turns dark hours before eclosing (emerging). Photo by Becky Yeager
Milkweed is the only host plant of the monarch caterpillar. Utah's most prolific milkweed Asclepias speciosa, or "showy milkweed," can sometimes be confused with dogbane, which grows in many of our canyons and has much more delicate flowers. For more help with identifying native milkweed in Utah, click HERE.
Showy milkweed (Asclepias speciosa) in bloom in Salt Lake City, Utah
NOT milkweed. This is dogbane in bloom in Utah.
For more help identifying monarchs throughout their life cycle and to watch a great video developed by National Geographic, click HERE.