Monarch Butterfly – Species Profile & Facts

There are few butterfly species in the world as recognizable as the Monarch (Danaus Plexippus) if any. This large and beautiful butterfly is famous for a lot of things, but primarily its trademark migration event. When spring arrives, millions of Monarchs will traverse thousands of miles from New Mexico to Northeast US and Canada to lay eggs.

The next generation of Monarch butterflies will make the same journey back when winter arrives to escape the cold season. This migration is ranked as one of the most impressive natural events on the Globe for good reasons. There’s nothing as outstanding as a million of Monarchs eclipsing the spring sun.

But there’s more to this species than its migration behavior. Let’s see what makes the Monarch butterfly so famous and beloved worldwide.

How to Recognize a Monarch Butterfly?

The Monarch has one of the most iconic looks in the butterfly kingdom. The Monarch is orange in color, but it can come in various nuances, including darker yellow and even orange-red. Both its forewings and hindwings display a black veiny pattern, reminding of a spider’s web. An interesting aspect is that all Monarchs display pretty much the same pattern, making them almost identical in appearance.

They mainly differ from one another via their color shading and subtle pattern variations in the white spots visible on the side of the wings. The same white spots typically cover the butterfly’s head and torso and, sometimes, even the abdomen.

There are few, slight differences between male and female Monarchs since they showcase similar sizes, colors, patterns, and wingspans. It may be tricky to differentiate between them without some in-depth knowledge on the species.

The key difference rests in the 2 black spots that the male will display on its hindwings, one on each wing. They are rather small but clearly visible, no matter the butterfly’s color intensity.

What Does a Monarch Butterfly Caterpillar Looks Like?

The Monarch caterpillar is probably one of the most handsome ones in the butterfly world. Caterpillars typically look nothing like adult butterflies, and the same is the case with this one. The difference is that most caterpillars are rather grotesque in appearance compared to the elegance of the adults.

This isn’t the case with the Monarch caterpillar which displays a unique appearance. An even more interesting aspect is that this species’ caterpillar changes appearance between its various instars (molting phases). Here’s what I mean:

  • First molt – The larva is born with a small (0.2 inches at most), green, and translucent body and a black head. As the second instar approaches, the caterpillar will display 2 small bumps on its head. These will eventually grow into the larva’s iconic tentacle-like antennae. This phase is also when the caterpillar will display its first iteration of the black transverse bands.
  • Second molt – The caterpillar’s transversal stripes change color slightly, mixing white with yellow and black for a more distinct look. This is when the Monarch caterpillar will begin to display its first setae (short hairs) and grow its black tentacles on its thorax and abdomen. The thoracic ones will be longer.
  • Third molt – At this point, the caterpillar will measure around 0.4 to 0.6 inches, and its appearance will change slightly. The stripes grow more distinct, and the tentacles become longer.
  • Fourth molt – Its banding pattern will change as the caterpillar now displays multiple bands covering its entire body, except for the blackhead.
  • Fifth molt – The caterpillar is now around 1 to 1.7 inches long and display an intricate body pattern towards the end of the instar. This is the last phase, marking the caterpillar’s final form before pupating.

Generally speaking, the 5 instars occur over a period of 3 to 5 days, but that depends on the environmental conditions. The entire stage-based growth process will speed up dramatically in warmer environments that are also abundant in food.

How Big Does a Monarch Butterfly Get?

The Monarch butterfly can get up to 3-4 inches in most cases, but they vary in size based on a variety of factors. Environmental conditions and available food are the most important ones, influencing the butterfly’s development considerably.

It’s also worth noting that male Monarchs are slightly larger than females, with the situation being the other way around for most butterflies and insect species. However, that’s not a valid marker to use when looking to differentiate between male and female Monarchs. Instead, rely on the male’s black spots visible on its hindwings; all-male Monarchs have them.

Where do Monarch Butterflies Live?

Monarchs are more widespread throughout the US, from South America to South Canada. But Monarchs aren’t bound to this area. They have also adapted to a multitude of systems throughout the Globe, including the Philippines, Morocco, Australia, New Zealand, and others.

Monarchs prefer warmer regions, leading overwintering species to migrate when the cold season approaches. This behavior has allowed the butterfly to spread to other areas faster than other species. Young Monarchs will leave their native region when winter approaches to breed, while new generations of Monarchs will return to their parents’ native lands to give birth to their own offspring.

This cycle repeats yearly, leading to mass Monarch sightings which can turn overwhelming fast.

What do Monarch Butterflies Eat?

The Monarch’s eating habits differ than many other species in 2 areas:

  1. The larvae’s eating habits – The Monarch caterpillar only consumes milkweed leaves. This plant is part of the Asclepias genus and other similar plants, known for their milky, latex-like substance that the plant will produce when damaged. These plants contain substances known as cardiac glycosides, a term that is ominous enough on its own. These are toxins to humans and most creatures, but not the Monarch caterpillar. The caterpillar consumes the plant for nourishment and the toxic protection it provides against the numerous predators that have the Monarch on their meal list.
  2. The adult’s eating habits – Monarchs have a more varied diet than most butterfly species. While other butterflies only stick to a small number of flowers, Monarchs have a variety as their favorites. Some of the most relevant plants and flowers they prefer include coneflowers, Indian hemp, teasel, horseweed, common boneset, goldenrod, lilac, red clover, and numerous species of milkweed. The fact that the adult butterfly also consumes milkweed is evidence of its poisonous nature if its coloring wasn’t enough.

What Plants Attract Monarch Butterflies?

Monarchs, like most butterflies, are largely attracted by very colorful flowers, preferably in the pink and purple range. Some of the Monarch’s favorites include milkweed, dwarf butterfly bushes, zinnia, Brazilian verbena, and others.

These are common flowers that can appear in gardens and pretty much anywhere the environmental conditions allow them. If you aim to attract Monarchs to your garden, use some of these plants to garner their interest, and they won’t be late to the party.

How do Monarch Butterflies Reproduce?

The Monarch’s reproductive cycle begins with the mating phase, which is something to behold in and of itself. The mating period occurs in 2 stages:

  1. Aerial phase – The male stalks the female in mid-air, catches it and forces it to the ground. It is somewhat a forceful act since female Monarchs never go with a male willingly. The male’s persistence and commitment is what convince the female that he’s worthy.
  2. Ground phase – The male will inseminate the female over a period of 30 to 60 minutes. They will remain attached during that time

Several interesting aspects are worth mentioning here. First is the fact that only 30% of the mating attempts are successful, mostly due to the females’ rejection of weaker males. Second, male Monarchs transfer their sperm in a spermatophore, a structure containing the male’s spermatozoa and additional nutritional elements meant to nourish the female until she lays the eggs.

Third, males will typically only fertilize some of the female’s eggs, not all. The larger the spermatophore, the more eggs will be fertilized, which is why female Monarchs typically prefer larger males.

Once the mating is complete, the female begins to search for a place to lay the eggs, triggering the Monarch’s reproductive cycle. The Monarch will go through 4 phases, like all Lepidoptera:

  • Egg – Female Monarchs look for milkweed plants and lay their eggs on the underside of their leaves. The egg-laying process may last between 2 to 5 weeks, during which the female may lay up to 500 eggs on average, depending on how successful the fertilization process has been. She will cover the eggs in a sticky substance, holding them together against the leaf and protecting them against the elements. As a useful note, female Monarchs can mate several times and may even lay up to 1,800 eggs, provided it has had very fertile partners.
  • Larva – We’ve already discussed the Monarch caterpillar and its 5-instar growth pattern. In addition, the caterpillars can display aggressive behavior when food competition is fierce. Monarch caterpillars do one thing around the clock – eat. If there isn’t enough food for all of them, they might become aggressive and even kill each other.
  • Pupa – Once the caterpillar has completed its 5 molting phases, it will look for a safe and secluded space and turn into a pupa by shedding its old skin and revealing a green and amorphous chrysalis. The chrysalis will harden over the following hours, at which point it will appear as a sarcophagus with a rim around the upper dorsal area and several yellow dots on its lower portion. The caterpillar will pupate for almost 2 weeks, depending on the environmental conditions. In warm weather, that period may be cut in half.
  • Adult – You can tell that the adult Monarch is about to hatch by the way the pupa looks. The chrysalis will become transparent around 24 hours before hatching, revealing the adult Monarch tucked inside. The butterfly will display its trademark black and orange colors as it prepares to hatch soon. Upon hatching, the Monarch will rest for some time, pumping air and blood into its wings and waiting for them to dry out. It will then fly away to look for food. The Monarch usually becomes sexually mature several days after the metamorphosis process is complete.

As soon as the adult Monarch becomes sexually viable, it will begin looking for a mate, and the butterfly’s life cycle resets.

Where do Monarch Butterflies Lay Their Eggs?

Monarchs always lay their eggs on the milkweed leaves. Fortunately, there are several species of milkweed that the larvae accept as food. These include:

  • Heartleaf milkweed
  • Swamp milkweed
  • Caribbean milkweed
  • Antelope Horns milkweed
  • Desert milkweed and many others

The female Monarch will use a gluey substance to stick the eggs on the underside of the plant’s leaves. These will keep them out of sight, making it harder for predators to spot them. Even so, not all eggs will survive.

Are Monarch Butterflies Rare?

Monarch butterflies are still seen in millions during their migratory phase, but recent studies have revealed their numbers are dwindling. Several reasons are to blame for that, including pesticides, widespread agricultural practices, illegal logging, and climate changes, to name a few.

Out of all these issues, deforestation is probably the most severe, affecting the butterfly’s habitat by destroying the natural cultures of milkweed. Although the number of Monarchs is still high, it goes down rapidly, causing concern among experts.

Is the Monarch Butterfly Endangered?

Not yet, but it seems to be heading that way. Canada has currently ranked the species as special concern, pushing to list it as endangered as of 2016.

The US Fish and Wildlife organization provided the Monarch with the ‘candidate’ status under the Endangered Species Act in 2020. This means that the butterfly’s population will be assessed yearly, as will its listing. If the Monarch population continues to drop at the same rate, the butterfly will make its way on the list of endangered species.

How Long Do Monarch Butterflies Live?

Between 2 to 6 weeks. This is the standard lifespan of a Monarch, given optimal living conditions. Overwinter species, however, will live longer, up to 9-10 months.

The Monarch’s lifespan is typically influenced by environmental factors like climate, food availability, and mating opportunities. The male will die soon after mating since it will have achieved its biological goal. The female will live long enough to lay its eggs, which may last days or even weeks.

What is the Meaning of Monarch Butterfly?

The legend goes that the Monarch butterfly got its name from that of King William III of England, more precisely one of the king’s titles – Prince of Orange. As any other legend, this one hasn’t been confirmed either, but it sure sounds good.

Whether the butterfly’s name is of royal descent or not, it doesn’t matter. It’s looks is royal enough as it is.

Is the Monarch Butterfly Poisonous?

Yes, it is. The Monarch’s poisonous nature comes from the caterpillar’s feeding habits. Since the latter feeds almost exclusively on milkweed, the plant’s toxic substances pass on to the caterpillar and into the adult butterfly’s system. The butterfly’s strident colors tell the story of an uneatable insect that most predators will immediately notice.

The Monarch’s survival rate is fantastic, thanks to this beneficial evolutionary feature. It is so fantastic that another butterfly species has evolved to mimic the adult Monarch almost atom by atom.

It is none other than Kentucky’s official butterfly, the Viceroy. This species is almost identical to the Monarch in coloring and pattern, with slight differences. However, the Viceroy is smaller than the Monarch, and its color pattern is not identical to the latter.

The Viceroy displays an almost horizontal line traversing its hind wings and has no white spots on its thorax. Other than that, the resemblance between the 2 species is uncanny.


The Monarch is a staple species in the butterfly world. It is most famous for its migratory behavior, ravishing look, and gregarious tendencies.

Plant some of the butterfly’s favorite flowers in your garden and, if you live around its natural habitat, the Monarch will visit you soon enough.

Butterflies   Updated: January 28, 2022
avatar Welcome to Insectic, a blog to learn about insects and bugs. I'm Richard, and I've created this website to share my experience, knowledge, and passion with others.

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